WordDefinitionFrench translation
3' - endThe end of a polynucleotide with a free (or phosphorylated) 3' - hydroxyl group.Polynucléotide partie 3'
5' - endThe end of a polynucleotide with a free (or phosphorylated or capped) 5' - hydroxyl group; transcription/translation begins at this end.Polynucléotide partie 5'
Acceptor splice siteThe boundary between the 3' end of an intron and the 5' end of the adjacent exon.
AchondroplasiaThe most common and well known form of short limbed dwarfism characterized by a normal trunk size with disproportionally short arms and legs, and a disproportionally large head; autosomal dominant condition.Achondroplasie
AlleleAn alternative form of a gene; any one of several mutational forms of a gene.Allèle
AllogeneicThe allelic variation seen among members of the same species.Allogénique
Alu repetitive sequenceThe most common dispersed repeated DNA sequence in the human genome accounting for 5% of human DNA. The name is derived from the fact that these sequences are cleaved by the restriction endonuclease Alu.Séquences répétitives Alu
Amino acidBiologically important organic compounds made from amine (-NH2) and carboxylic acid (-COOH) functional groups, along with a side-chain specific to each amino acid. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen, though other elements are found in the side-chains of certain amino acids. About 500 amino acids are known and can be classified in many ways. Structurally they can be classified according to the functional groups' locations as alpha- (α-), beta- (β-), gamma- (γ-) or delta- (δ-) amino acids; other categories relate to polarity, pH level, and side chain group type (aliphatic, acyclic, aromatic, containing hydroxyl or sulphur, et al.). In the form of proteins, amino acids comprise the second largest component (after water) of human muscles, cells and other tissues. Outside proteins, amino acids perform critical roles in processes such as neurotransmitter transport and biosynthesis.Acide aminé
Amino acid sequenceThe linear order of the amino acids in a protein or peptide.Séquence d'acides aminés
AmniocentesisPrenatal diagnosis method using cells in the amniotic fluid to determine the number and kind of chromosomes of the fetus and, when indicated, perform biochemical studies.Amniocentèse
AmniocyteCells obtained by amniocentesis.
AmplificationAny process by which specific DNA sequences are replicated disproportionately greater than their representation in the parent molecules.Amplification
AneuploidyState of having variant chromosome number (too many or too few). (i.e. Down syndrome, Turner syndrome).Aneuploïdie
Angelman syndromeA condition characterized by severe mental deficiency, developmental delay and growth deficiency, puppet-like gait and frequent laughter unconnected to emotions of happiness.Syndrome d'Angelman
AnticipationPhenomenon in which the severity of a genetic condition appears to become more severe and/or arise at an earlier age with subsequent generations (seen in many trinucleotide repeat permutations).Anticipation
Apert syndromeA condition caused by the premature closure of the sutures of the skull bones, resulting in an altered head shape, with webbed fingers and toes. Autosomal dominant.Syndrome d'Apert
ApoptosisProgrammed cell death; a physiologic process conserved to remove unwanted cells.Apoptose
Artificial inseminationThe placement of sperm into a female reproductive tract or the mixing of male and female gametes by other than natural means.Insémination artificielle
AscertainmentThe selection of individuals for inclusion in a genetic study (severity, age of onset, certain features of the trait).Régulation
AssociationIn a specific population, the occurrence together of 2 or more different phenotypes more often than expected by chance.Association
ATPAbbreviation for adenosine triphosphate. The energy-yielding molecule in cells that is used to drive chemical reactions.ATP
AutophagyDigestion of the cell's own organelles.Autophagie
AutoradiographA photographic picture showing the position of radioactive substances in tissues.Autoradiographie
Autosomal diseaseA disease encoded by a gene on one of the 22 pairs of autosomes.Maladie autosomale ou génétique
Autosomal dominantA trait that is expressed in an individual who is heterozygous for a particular gene when the mutant allele is on one of the autosomes.Maladie autosomale dominante
Autosomal modifierGene A gene that modifies the action of the autosomes.Gène modificateur autosomal
Autosomal recessiveA trait that is expressed in an individual who is homozygous for a particular gene.Maladie autosomale récessive
AutosomeAny chromosome other than the X or Y. Humans have 22 pairs of autosomal chromosomes.Autosome
BACSee bacterial artificial chromosome.BAC
BackcrossA genetic crossing of a heterozygous organism and one of its homozygous parents.Rétrocroisement
Bacterial artificial chromosome (BAC)Artificial chromosome vector derived from bacteria used for cloning relatively large DNA fragments.Chromosome artificiel de bactérie
BacteriophageA virus whose host is a bacterium; commonly called phage.Bactériophage
Balanced translocationA rearrangement translocation with no apparent loss or gain of chromosomal material, resulting in a clinically normal but genetically "abnormal" person.Translocation balancée ou équilibrée
BandingThe differential staining of a chromosome by a variety of techniques that results in a specific pattern of positively and negatively stained bands for each chromosomal pair.Coloration différentielle des chromosomes
Barr bodyThe sex chromatin mass located adjacent to the nuclear membrane in interphase nuclei, which corresponds to an inactivated X chromosome. One Barr body is seen in the cells of 46,XX and 47,XXY individuals, and none in the cells of 45,X and 46,XY individuals. The condensed single X-chromosome seen in the nuclei of somatic cells of female mammals. base pair a pair of hydrogen-bonded nitrogenous bases (one purine and one pyrimidine) that join the component strands of the DNA double helix.Corpuscule de Barr
Base analogueA substance that can mimic the chemical behavior of 1 of the 4 DNA bases.Analogue de base
Base pair substitutionThe replacement of 1 base pair by another.Substitution par une paire de bases
Base sequenceA partnership of organic bases found in DNA and RNA; adenine forms a base pair with thymine (or uracil) and guanine with cytosine in a double-stranded nucleic acid molecule.Séquence de bases
Bayesian analysisMathematical method for calculating probability of the carrier state in mendelian disorders by combining several independent likelihoods. A mathematical method to further refine recurrence risk taking into account other known factors.Analyse Bayesienne
Becker muscular dystrophyX-linked condition characterized by progressive muscle weakness and wasting; manifests later in life with progression less severe than Duchenne muscular dystrophy.Dystrophie musculaire de Becker
BioinformaticsThe discipline of using computers to address information problems in the life sciences; it involves the creation of electronic data bases on genomes, protein sequences, etc.Bioinformatique
BivalentA pair of homologous chromosomes in association as seen at metaphase of the first meiotic division.Bivalent
CAG/CTGRepeats Abbreviation for cytosine-adenine-guanine triplet nucleotide and cytosine-thymine- guanine triplet nucleotide repeats; they are associated with unstable mutations.CAG/CTG
Candidate geneA gene known to be located in the region of interest whose product has biochemical or other properties suggesting that it may prove to be the disease gene being sought.Gène candidat
Candidate gene approachStrategy to identify disease-associated genes based on finding candidate genes in a chromosome region in which a disorder is mapped.Approche gène candidat
CapA modified nucleotide added to the 5' end of a growing mRNA chain, apparently required for normal processing, stability, and the translation of mRNA.Coiffe
Cap siteThe site of initiation of transcription.Site d'initiation de transcription
CarrierAn individual heterozygous for a single recessive gene.Porteur hétérozygote
CAT assayReporter gene assay used to measure activity of a promoter under different conditions, such as to define elements of a promoter or to study signals that activate an intact enhancer/promoter. CAT is the abbreviation for the enzyme, chloramphenicol acetyl transferase, the activity of which is measured in the assay.Gene rapporteur
CDNAComplementary DNA produced from a RNA template by the action of RNA- dependent DNA polymerase.ADNc
Cell lineA cultured cell type that can be reproduced indefinitely, is, immortalized.Lignée cellulaire
CentromereA region of a chromosome to which spindle traction fibers attach during mitosis and meiosis; the position of the centromere determines whether the chromosome is considered an acrocentric, metacentric or telomeric chromosome.Centromère
CG islandUnmethylated cytosine-guanine sequences that are often found near the 5' ends of some genes.Ilots CpG
Chain termination mutationA mutation that generates a stop codon, thus preventing further synthesis of the polypeptide chain.Mutation codon non-sens
Charcot-Marie Tooth diseaseA condition characterized by degeneration of the motor and sensory nerves that control movement and feeling in the arm below the elbow and the leg below the knee; transmitted in autosomal dominant, autosomal recessive and X-linked forms.Maladies de Charcot-Marie-Tooth
Chorionic villus samplingAn invasive prenatal diagnostic procedure involving removal of villi from the human chorion to obtain chromosomes and cell products for diagnosis of disorders in the human embryo.Échantillon de villus chorionic
ChromosomeIn the eukaryotic nucleus, one of the threadlike structures consisting of chromatin and carry genetic information arranged in a linear sequence.Chromosome
Chromosome aberrationAn abnormality of chromosome number or structure.Aberration chromosomique
Chromosome bandingA technique for staining chromosomes so that bands appear in a unique pattern particular to the chromosome.Coloration différenciée des chromosomes
Cleft lip/palateCongenital condition with cleft lip alone, or with cleft palate; cause is thought to be multifactorial.Fissure palatine
Clinical geneticsThat part of medical genetics concerned with health and illness in individuals and families.Génétique clinique
Clinical heterogeneityRefers here to the production of clinically different phenotypes from mutation in the same gene.Hétérogénéité des cas cliniques
CloneGenetically engineered replicas of DNA sequences.Clône
Cloned DNAAny DNA fragment that passively replicates in the host organism after it has been joined to a cloning vector.ADN cloné
CodominanceThe expression of both alleles in a heterozygous individual, e.g., presence of both hemoglobin A and S on electrophoresis in an individual heterozygote for sickle-cell disease.Codominance
CodonA sequence of three nucleotides in mRNA that specifies an amino acid.Codon
Complementary DNA (cDNA)DNA synthesized from an mRNA template, using reverse transcriptase.ADNc ou ADN complémentaire
Complementation analysisA genetic test for determining whether 2 mutations producing a similar phenotype are allelic.Analyse par complémentation
ConcordancePresence of the same trait in both members of a pair of twins (or set of individuals).Concordance
Confined placental mosaicismMosaicism that is seen only in the placenta but not in the fetus.Mosaïque placentaire spécifique
Congenic mouse strainA strain that differs from another in the region containing 1 genetic locus.Souris isogéniques
ConsanguinityGenetic relationship. Consanguineous individuals have at least one common ancestor in the preceding few generations.Consangunité
Conservative changeAn amino acid change that does not affect significantly the function of the protein.Substitution conservative
ConsultandIndividual seeking, or referred for, genetic counseling.Individus à orientation génétique
ContigA series of contiguous, overlapping, cloned DNA fragments.Séquence génomique continue ou contig
Contiguous genesGenes physically close on a chromosome that when acting together express a phenotype.Gènes contigus
Copy numberThe number of copies of a transgene integrated into a host genome; used to describe transgenic animals.Nombre de copie
Cornelia de Lange syndromeCondition involving growth deficiency, significant developmental delay, anomalies of the extremities and a characteristic facial appearance.Syndrome de Cornelia de Lange
CosmidsPlasmid vectors designed for cloning large fragments of eukaryotic DNA; the vector is a plasmid into which phage lambda cohesive end sites have been inserted.Cosmides
CpG islandsAreas of multiple CG repeats in DNA.Ilots CpG
Cri-du-chat syndromeA chromosomal condition (monosomy 5p). Name comes from the distinctive mewing cry of affected infants; characterized by significant mental deficiency, low birthweight, failure to thrive and short stature; deletion of a small section of the short arm of chromosome 5.Syndrome de Lejeune ou syndrome du cri du chat
Crossing overReciprocal breaking and rejoining of homologous chromosomes in meiotic prophase I that results in exchange of chromosomal segments.Enjambement chromosomique
CrossoversThe exchange of genetic material between two paired chromosome during meiosis.Enjambement
Cystic fibrosisAn autosomal recessive genetic condition of the exocrine glands, which causes the body to produce excessively thick, sticky mucus that clogs the lungs and pancreas, interfering with breathing and digestion.Mucoviscidose
CytogeneticsThe study of chromosomes.
Degenerate codonA codon that specifies the same amino acid as another codon.Dégénérescence du code
DeletionLoss of part or a whole chromosome or loss of DNA nucleotide bases.Délétion
Deletion mappingThe use of overlapping deletions to localize the position of an unknown gene on a chromosome or linkage map.Carte de délétion
DicentricRefers to an aberrant chromosome that contains 2 centromeres.Chromosome dicentrique
DiploidThe number of chromosomes in most somatic cells, which is double the number found in the gametes (the haploid number). In humans, the diploid chromosome number is 46.Diploïde
DiscordantA twin pair (or set of individuals) in which one member exhibits a certain trait and the other does not.Discordant
DiseaseAny deviation from the normal structure or function of any part, organ, or system of the body that is manifested by a characteristic set of symptoms and signs whose pathology and prognosis may be known or unknown.Maladie
DizygoticThe product of fertilization of 2 separate eggs by 2 separate sperm; nonidentical twin pair.Dizygotiques
DMDDuchenne muscular dystrophy.Myopathie de Duchenne (DMD)
DNA constructA DNA sequence that has been modified to yield a recombinant DNA molecule.ADN artificiel
DNA fingerprint techniqueA method employed to determine differences in amino acid sequences between related proteins; relies upon the presence of a simple tandem-repetitive sequences that are scattered throughout the human genome.Profil génétique
DNA hybridizationA technique for selectively binding specific segments of single-stranded (ss) DNA or RNA by base pairing to complementary sequences on ssDNA molecules that are trapped on a nitrocellulose filter.Hybridation ADN
DNA LigaseAn enzyme that functions in DNA repair.ADN ligase
DNA ligaseEnzyme that catalyzes religation (reconnection) of 2 fragments of DNA.ADN ligase
DNA probeAny biochemical used to identify or isolate a gene, a gene product, or a protein.Sonde d'ADN
DNA rearrangementsRecombination of DNA segments, eg, in cells of the immune system, the variable (V), diversity (D), and joining (J) regions somatically rearrange to generate functional antibody genes.Réarrangement de l'ADN
DNA sequencing"plus and minus" or "primed synthesis" method, developed by Sanger, DNA is synthesized in vitro in such a way that it is radioactively labeled and the reaction terminates specifically at the position corresponding to a given base; the "chemical" method, ssDNA is subjected to several chemical cleavage protocols that selectively make breaks on one side of a particular base.Séquençage de l'ADN
DOEDepartment of Energy.Département de l'Énergie des États-Unis
DominantAlleles that determine the phenotype displayed in a heterozygote with another (recessive) allele.Dominant
Dominant (trait)Those conditions that are expressed in heterozygotes, ie, individuals with 1 copy of the mutant gene and 1 copy of the normal allele; refers to phenotype.Caractère dominant
Donor siteGuanine-thymidine sequence that defines the splice site at the 5' end of an intron.Site donneu des introns
Double heterozygoteAn individual with 1 mutant allele at each of 2 different loci.Double hétérozygote
Down syndromeA type of mental deficiency due to trisomy (three copies) of autosome 21, a translocation of 21 or mosaicism.Syndrome de Down
Duchenne/Becker muscular dystrophyThe most common and severe form of muscular dystrophy; transmitted as an X-linked trait. X-linked recessive. Symptoms include onset at 2-5 years with difficulty with gait and stairs, enlarged calf muscles, progression to wheelchair by adolescence, shortened life span.Myopathie de Duchenne (DMD)
DuplicationThe presence of an extra copy of chromosome material. At the gene level, this refers to the presence of more than 1 copy of a structured gene, usually having arisen through unequal crossing over. At the chromosomal level, this refers to an unbalanced state in which there may be a triple dose of a portion of an autosome, usually occurring as the result of unequal segregation of a translocation in meiosis (trisomy).Duplication
DwarfismConditions of short stature with adult height under 4'10" as adult, usually with normal intelligence and lifespan. Ehlers Danlos Syndrome connective tissue condition including problems with tendons, ligaments, skin, bones, cartilage, and membranes surrounding blood vessels and nerves. Symptoms include joint laxity, elastic skin, dislocations. Many forms: autosomal dominant, autosomal recessive, X-linked forms.Nanisme
DystoniaNeurologic condition involving repeated twisting and movement. Involves a variety of muscle groups. Intelligence not effected. Three forms: childhood - autosomal dominant, autosomal recessive, adult-acquired.Dystonies
Ecogenetic disorderA disorder resulting from the interaction of a common environmental factor with a specific genetic predisposition, e.g., cigarette smoking causing emphysema in alpha- antitrypsin deficiency.Trouble écogénétique
ElectroporationApplication of a short, high-voltage electric pulse to cells in the presence of DNA to permit DNA to enter the cells.Électroporation
ELSIEthical, legal and social implications (of HGP). The National Human Genome Research Institute's (NHGRI) Ethical, Legal and Social Implications (ELSI) Research Program was established in 1990 as an integral part of the Human Genome Project (HGP) to foster basic and applied research on the ethical, legal and social implications of genetic and genomic research for individuals, families and communities. The ELSI Research Program funds and manages studies, and supports workshops, research consortia and policy conferences related to these topics.ELSI
Embryo biopsyPotential method for preimplantation diagnosis of genetic disorders used in conjunction with in vitro fertilization in which cells are removed and analyzed at a very early stage in embryonic development.Diagnostique génétique préimplantatoire
Embryonic stem cellsCells derived from early embryos that can replicate indefinitely and differentiate into many cell types. Stem cells serve as a continuous source of new cells; they may become incorporated into many tissues to produce chimeric animals when introduced into early embryos, i.e., blastocysts.Cellules souches embryonnaires
Empiric riskRisk of recurrence for multifactorial or polygenic disorders based on family studies (observed risk).Gestion empirique des bénéfices/risques
EndonucleaseEnzyme that cleaves bonds between nucleotides of single- or double-stranded DNA or of RNA at specific sequences of nucleotides.Andonucléase
Env geneEncodes capsule or envelope protein of a retrovirus.Protéine de la capside rétrovirale
EpigeneticA factor that changes the phenotype without changing the genotype.Épignétique
EpisomeA plasmid that can exist either independently in the cytoplasm or as an integrated part of the genome of its bacterial host.Épisome
ErythrocytesThe hemoglobin-containing cell found in the blood of vertebrates.Érythrocyte
ES cellsSee embryonic stem cells.Cellules Souches
ESTSee expressed sequence tag.Marqueur de séquence exprimée
EthicsThe study of fundamental principles which defines values and determines moral duty and obligation.Éthique
EuchromatinThe chromatin that shows the staining behavior characteristic of the majority of the chromosomal complement.Euchromatine
EugenicsThe improvement of humanity by altering its genetic composition by encouraging breeding of those presumed to have desirable genes.Eugénisme
ExonsPortion of a gene included in the transcript of a gene and survives processing of the RNA in the cell nucleus to become part of a spliced messenger of a structural RNA in the cell cytoplasm; an exon specifies the amino acid sequence of a portion of the complete polypeptide.Exons
ExonucleaseAn enzyme that cleaves nucleotide chains at their terminal bonds only.Exonucléase
Expressed sequence tagA short fragment of an expressed sequence, cDNA, which serves as a landmark for gene mapping.Marqueur de séquence exprimée
ExpressionThe observable effects of an active gene.Expression
ExpressivityThe degree to which a heritable trait is expressed in an individual. "Variable expressivity" refers to the variation in phenotype and in severity produced by the same gene in different individuals.Niveau d'expression
F1 hybridsThe first generation of animals/plants generated from 2 different (inbred) strains. In case of inbred, these animals/plants are genetically identical to one another but different from either inbred parent.Hybrides F1
F2 hybridsThe progeny produced from matings between F1 animals/plantes. These animals/plants are different from one another and will contain different mixtures of the genetic variations that were present in the original (inbred) progenitors.Hybrides F2
Fetal alcohol syndromeA link between excessive alcohol consumption during pregnancy and birth defects; characteristics include small head and eyes, folds of the skin that obscure the inner juncture of the eyelids, short, upturned nose, and thin lips.Syndrome d’alcoolisation fœtale
FISHFlorescent in situ hybridization: a technique for uniquely identifying whole chromosomes or parts of chromosomes using florescent tagged DNA.Hybridation fluorescente in situ
Flanking sequenceA region of a gene preceding or following the transcribed region.Séquences flanquantes
Footprinting (DNA footprinting)Assay used to study DNAbinding proteins.Empreinte génétique
FounderRefers to animals generated from genetically altered eggs or embryos, is, eggs microinjected with a transgene.Fondateur
Founder effectThe high frequency of a mutant gene in a rapidly expanding population founded by a small ancestral group when 1 or more of the founders were, by chance, carriers of the mutant gene.Effet fondateur
Fragile sitesA non-staining gap of variable width that usually involves both chromatids and is always at exactly the same point on a specific chromosome derived from an individual or kindred.Sites fragile
Fragile-X syndromeX-linked trait; the second most common identifiable cause of genetic mental deficiency.Syndrome de l’X fragile
GameteAn haploid cell.gel electrophoresis the process by which nucleic acids (DNA or RNA) or proteins are separated by size according to movement of the charged molecules in an electrical field.Gamète
Gel-shiftAssay An assay used to detect specific protein binding to DNA. Such binding creates complexes that migrate more slowly during gel electrophoresis than free DNA. Also known as mobility-shift assay.Retard sur gel
GeneA hereditary unit that occupies a certain position on a chromosome; a unit that has one or more specific effects on the phenotype, and can mutate to various allelic forms.Gène
Gene amplificationAny process by which specific DNA sequences are replicated disproportionately greater than their representation in the parent molecules; during development, some genes become amplified in specific tissues.Amplification de gène
Gene bankGene banks are a type of biorepository which preserve genetic material. In plants, this could be by freezing cuts from the plant, or stocking the seeds. In animals, this is the freezing of sperm and eggs in zoological freezers until further need. With corals, fragments are taken which are stored in water tanks under controlled conditionsBanque de gènes
Gene family, multiple genesA group of genes having similar DNA sequence evolved from a single ancestral gene. These genes may or may not be located in the same region of a chromosome.Famille de gènes
Gene flowGradual diffusion of genes from one population to another, as a result of migration and intermarriages.Flux de gènes
Gene mapThe linear arrangement of mutable sites on a chromosome as deduced from genetic recombination experiments.Carte génétique
Gene therapyA strategy in which therapeutic genes are introduced into a person's cells to correct a disease or genetic flaw.Thérapie génique
Gene therapyAddition of a functional gene or group of genes to a cell by gene insertion to correct an hereditary disease.Thérapie génique
Genetic codeThe base triplets that specify the 20 different amino acids.
Genetic counselingThe educational process that helps individuals, couples, or families to understand genetic information and issues that may have an impact on them.Orientation génétique
Genetic driftRandom fluctuations in gene frequencies, most evident in small populations.Dérive génétique
Genetic heterogeneityDifferent mutations causing a similar phenotype; allelic heterogeneity refers to different mutations at the same locus, whereas locus heterogeneity refers to mutations at different loci.Hétérogénéité génétique
Genetic lethalA genetic disease that prevents fertility.Gène létal (ou léthal)
Genetic linkage mapA chromosome map showing the relative positions of the known genes on the chromosomes of a given species.Carte de liaison génétique
Genetic map, genetic mappingDetermination of the relative positions of genes on a DNA molecule (chromosome or plasmid); distances are measured in linkage units, i.e., centimorgans (cM), between them.Carte génétique
Genetic markerA polymorphic genetic property that can be used to distinguish the parental origin of alleles.Marqueur génétique
Genetic screeningTesting groups of individuals to identify defective genes capable of causing hereditary conditions.
Genetic variationA phenotypic variance of a trait in a population attributed to genetic heterogeneity.
GenomeAll of the genes carried by a single gamete; the DNA content of an individual, which includes all 44 autosomes, 2 sex chromosomes, and the mitochondrial DNA.
GenotypeGenetic constitution of an organism.Génotype
Germ cellA sex cell or gamete (egg or spermatozoan).Haldane equation Haldane's law: the generalization that if first generation hybrids are produced between two species, but one sex is absent, rare, or sterile, that sex is the heterogamic sex.Cellule germinale
HAAbbreviation for heteroduplex analysis.Analyse des hétéroduplex
HaplotypeA set of closely linked genes that tends to be inherited together as a unit, as occurs with the A, B. and C loci of the human leukocyte antigen (HLA) gene complex.Haplotype
Hardy-Weinberg LawThe concept that both gene frequencies and genotype frequencies will remain constant from generation to generation in an infinitely large, interbreeding population in which mating is at random and there is no selection, migration or mutation.Loi de Hardy-Weinberg
HemophiliaA sex-linked disease in humans in which the blood-clotting process is defective.Hémophilie
HeteroduplexRefers to a region of a double-stranded DNA molecule with noncomplementary strands that originated from different duplex DNA molecules.Hétéroduplex
HeterogeneityThe production of identical or similar phenotypes by different genetic mechanisms.Hétérogénéité
HeteromorphismA normal morphologic or staining variant of a chromosome.Hétéromorphisme
HeteroplasmyThe existence of more than 1 mitochondrial type in the cells of an individual, i.e., the presence of both normal and mutant mt DNA in a single individual.Hétéroplasmie
HeteroploidAn individual with an abnormal number of chromosomes (as compared to euploid, which is the normal number of chromosomes).Hétéroploïde
HeterotetramerA molecule consisting of 4 subunits, at least 1 of which differs from the others.Hétérotétramère
HeterozygoteHaving two alleles that are different for a given gene.Hétérozygote
HGPHuman Genome Project.HGP
HHMIHoward Hughes Medical Institute.HHMI
Homologous chromosomesChromosomes that pair during meiosis; each homologue is a duplicate of one chromosome from each parent.Chromosomes homologues
HomoplasmyThe presence of a single population of mt DNA in the cells of a single individual. This is normal.Homoplasmie
HomotetramerA molecule consisting of 4 identical subunits.Homotétramère
HomozygoteHaving identical alleles at one or more loci in homologous chromosome segments.Homozygote
Housekeeping geneThose genes expressed in all cells because they provide functions needed for sustenance of all cell types.Gène domestique
HUGOHuman Genome Organization.HUGO
Huntington diseaseA disease characterized by irregular, spasmodic involuntary movements of the limbs and facial muscles, mental deterioration and death, usually within 20 years of the onset of symptoms.Maladie de Huntington
Hybrid cellA cell formed by fusion of 2 cells of different origin in which the 2 nuclei have merged into 1. Can be cloned to produce hybrid cell lines.Hybridation cellulaire
HybridizationThe pairing of a single-stranded, labeled probe (usually DNA) to its complementary sequence.
IchthyosisAny of several hereditary or congenital skin conditions; skin of affected individuals has a dry, scaly appearance.Ichthiose
ImprintingA chemical modification of a gene allele which can be used to identify maternal or paternal origin of chromosome.Gène soumis à empreinte
In situRefers to carrying out experiments or tests with intact tissues.In situ
In situ hybridizationHybridization of a labeled probe to its complementary sequence within intact, banded chromosomes.Hybridation in situ
In vitroRefers to a biologic or biochemical phenomenon that occurs outside of a living organism.In vitro
In vivoRefers to a biologic or biochemical phenomenon that occurs within a living organism.In vivo
Inbred mouse strainA strain of mice that has been maintained by successive brother to sister matings over many generations, e.g., BALB/c and C57BL/6 mice strains.Lignée génétique de souris
Incomplete penetranceThe gene for a condition is present, but not obviously expressed in all individuals in a family with the gene.Pénétrance incomplète
InducerA molecule that induces the expression of a gene.Inducteur
Initiation factorA protein that associates with the small subunit of a ribosome when protein synthesis begins.Facteur d'initiation
Insertion mutagenesis, insertional mutagenesisThe production of a mutation by insertion of 1 or more copies of a transgene into a host genome.Mutagénèse par insertion
Intergenic DNAThe untranscribed DNA of unknown function that makes up a large proportion of the total DNA.ADN intergénique
IntronsA segment of DNA (between exons) that is transcribed into nuclear RNA, but are removed in the subsequent processing into mRNA.Introns
InversionA structural rearrangement of a chromosome in which 2 breaks occur, followed by the reinsertion of the chromosome segment but in reversed order. It may be either paracentric, i.e., it does not include the centromere, or pericentric, i.e., it does include the centromere.Inversion
IsochromosomeA metacentric chromosome produced during mitosis or meiosis when the centromere splits transversely instead of longitudinally; the arms of such chromosome are equal in length and genetically identical, however, the loci are positioned in reverse sequence in the two arms.Isochromosome
IsochromosomeA structural chromosome rearrangement caused by the division of a chromosome along an axis perpendicular to the usual axis of division; results in chromosomes with either 2 short arms or 2 long arms.Isochromosome
IsodisomyThe presence of 2 identical homologues of a transmitted chromosome from only 1 of the parents. junk DNA with no apparent function.Isodisomie
KaryotypeA set of photographed, banded chromosomes arranged in order from largest to smallest.Caryotype
KinetochoreA structure at the centromere to which the spindle fibers are attached.Kinétochore
Klinefelter syndromeAn endocrine condition caused by a an extra X-chromosome (47,XXY); characterized by the lack of normal sexual development and testosterone, leading to infertility and adjustment problems if not detected and treated early.Syndrome de Klinefelter
Lagging strand of DNAThe new strand of a DNA replicating in the 3' to 5' direction. It is synthesized in short fragments in the 5'to 3' direction that are subsequently joined together.Élongation ou synthèse de l'ADN
Lethal factorAn abnormality of the genome that leads to death in utero, e.g., numerous chromosomal anomalies.Facteur létal (ou léthal)
LigandA molecule that can bind to a receptor and thereby induce a signal in the cell, e.g., a hormone.Ligand
LinkageAnalysis of pedigree the tracking of a gene through a family by following the inheritance of a (closely associated) gene or trait and a DNA marker.Liaison génétique
LinkageThe greater association in inheritance of two or more nonallelic genes than is to be expected from independent assortment; genes are linked because they reside on the same chromosome.Liaison génétique
Linkage mapA chromosome map showing the relative positions of genetic markers of a given species, as determined by linkage analysis; not the same as a physical, or gene, map, which uses linkage analysis, cytogenetic examination, and physical techniques to generate the map.Carte de liaison génétique
Linkage phaseThe arrangement of alleles of linked loci on chromosomes.Phase de liason
Linker DNAA synthetic DNA that carries the recognition site for a restriction enzyme and that can bind 2 DNA fragments. Also, the stretch of DNA between 2 nucleosomes.
Lod scoreLogarithm of the odd score; a measure of the likelihood of two loci being within a measurable distance of each other.Logarithme des probabilités
Loss of heterozygosityDescribes a locus (or loci) at which a deletion or other process has converted the locus from heterozygosity to homozygosity or hemizygosity. Phenomenon can lead to cancers by loss of tumor suppressor genes.Perte d'hétérozygotie
LyonizationA term used for the phenomenon of X inactivation, which was first proposed by the geneticist Mary Lyon.Inactivation du chromosome X
Marfan syndromeAutosomal dominant condition of connective tissue; affects the skeletal, ocular and cardiovascular systems.Syndrome de Marfan
MarkerA gene with a known location on a chromosome and a clear-cut phenotype, used as a point of reference when mapping a new mutant.Marqueur
Maxam-Gilbert methodA method for determining the exact nucleotide sequence via a chemical degradation process.
MeiosisThe doubling of gametic chromosome number.
Mendelian inheritanceA trait obeying Mendel's first law of independent segregation of the alleles at the same locus conveyed by each parent.Hérédité Mendelienne
MethylationAddition of a methyl group (-CH3) to DNA or RNA.Méthylation
Methylmalonic acidemiaA group of conditions characterized by the inability to metabolize methylmalonic acid or by a defect in the metabolism of Vitamin B12.Acidémie méthylmalonique
Minimal promoterThe minimal elements of a promoter, including the TATA box and transcription initiation site, which is inactive unless regulatory elements that enhance promoter activity are placed upstream; used to test candidate sequences for enhancer activity.Promoteur minimal
MismatchThe presence in 1 chain of double-stranded DNA of a base that is not complementary to the corresponding base in the other chain. Also known as mispairing.Décalage
Missense mutationA change in the base sequence of a gene that alters or eliminates a protein.Mutation faux-sens
MitochondriaA small, intracellular, spherical to rod-shaped cytoplasmic organelle, enclosed by Z membranous spaces; the inner membrane is folded, forming a series of projections called cristae. Mitochondria are the principal sites of ATP synthesis; they contain enzymes of the tricarboxylic acid cycle and enzymes for fatty acid oxidation, oxidative phosphorylation, and many other biochemical pathways. They contain their own nucleic acids and ribosomes, replicate independently, and code for the synthesis of some of their own proteins.Mitochondrie
Mitochondrial DNAThe mitochondrial genome consists of a circular DNA duplex, with 5 to 10 copies per organelle.ADN mitochondrial
MitosisNuclear division.Mitose
Mobile elementsDNA sequences that are capable of inserting themselves into other locations in the genome.Éléments transposables
Mobility-shift assayAn assay used to detect specific protein binding to DNA. Such binding creates complexes that migrate more slowly during gel electrophoresis than free DNA. Also known as gel-shift assay.Retard sur gel
Modifier geneA gene that alters the expression of a gene at another locus.Gène modificateur
Molecular geneticsThe study of the structure and function of genes at the molecular level.Génétique moléculaire
Molecular hybridizationThe ability of a single-stranded DNA or RNA to anneal to its complementary single strand by Watson-Crick base pairing.Hybridation moléculaire
MonoclonalA group of cells that consist of a single clone, i.e., all cells are derived from the same single ancestral cell.Monoclonal
MonogenicDescribing a single gene or mendelian trait.Monogénique
MonosomyAn aneuploid condition in which a specific chromosome is present in only single copy, giving the individual a total of 45 chromosomes.Monosomique
MonozygoticRefers to twins derived from a single fertilized egg.Monozygotique
MorphogenA protein present in embryonic tissues in a concentration gradient that induces a developmental process.Morphogène
MosaicAn individual or tissue with at least 2 cell lines differing in genotype or karyotype, derived from a single zygote.Mosaïque
MRNAMessenger RNA; an RNA molecular that functions during translation to specify the sequence of amino acids in a nascent polypeptide.ARNm
MultifactorialA characteristic influenced in its expression by many factors, both genetic and environmental.Multifactoriel
Multipoint mappingA type of genetic mapping in which the recombination frequencies among 3 or more loci are estimated simultaneously.Carte multipoint
MurineRelating to mice or rats.Murin
MutagenA substance that causes a mutation.Mutagène
MutationProcess by which genes undergo a structural change.Mutation
Myotonic dystrophyA combination of progressive weakening of the muscles and muscle spasms or rigidity, with difficulty relaxing a contracted muscle; inherited as an autosomal dominant trait.Dystrophie myotonique de Steinert
NAIPNeuronal apoptosis inhibitory proteinNAIP (neuronal apoptosis inhibitory protein)
NeurofibromatosisOne of the most common single gene conditions affecting the human nervous system; in most cases, "cafe au lait" spots, are the only symptom; inherited as an autosomal dominant trait, with 50% being new mutations.Neurofibromatoses
NeurofibrominThe protein product of the neurofibromatosis type 1 gene.
New mutationAn alteration in DNA sequence that appears for the first time in a family as the result of a mutation in 1 of the parent's germ cell.Nouvelle mutation
NIHNational Institutes of Health.
NondisjunctionThe failure of homologous chromosomes (in mitosis or meiosis 1) or sister chromatics (in meiosis 11) to separate properly into different progeny cells.Non disjonction
NonpenetranceLack of clinical expression of the mutant phenotype in an individual with the appropriate genotype.Non pénétrance
Nonsense mutationA mutation in which a codon is changed to a stop codon, resulting in a truncated protein product.Mutation non-sens
Noonan syndromeA condition characterized by short stature and ovarian or testicular dysfunction, mental deficiency, and lesions of the heart.Syndrome de Noonan
Northern analysisA technique for transferring electrophoretically resolved RNA segments from an agarose gel to a nitrocellulose filter paper sheet via capillary action.Buvardage de northern
Nuclear familyA pair of biologic parents and their children.
NucleotideOne of the monomeric units from which DNA or RNA polymers are constructed; consists of a purine or pyrimidine base, a pentose sugar and a phosphoric acid group.Nucléotide
Nude miceImmunologically deficient mice used to permit growth of tumor cells from mouse and other species, such as human.Souris nue immunodéficiente
Null mutationAn allele that results in either the absence of the gene product or the absence of any function at the phenotypic level.Mutation nulle
Obligate heterozygoteAn individual who is clinically unaffected but, on the basis of pedigree analysis, must carry a particular mutant allele.Hétérozygote obligatoire
Oligogenic diseasesDiseases or traits that result from the effects of relatively few genes, some of which have rather large effects.Maladies oligogéniques
OligoprobeA short DNA probe whose hybridization is sensitive to a single base mismatch.Sonde oligo
OncogenesGenes involved in cell cycle control (growth factors, growth factor regulator genes, etc), a mutation can lead to tumor growth.Oncogènes
OncogenesNormal genes of vertebrates that are involved in control of cell growth and have been preserved throughout evolution. When mutated, overexpressed, or amplified in somatic cells, oncogenes may cause neoplastic transformation.Oncogènes
OrganellesMembrane-bound intracellular, cytoplasmic structures having specialized functions, e.g., mitochondria, plastics, Golgi apparatus, lysosomes.Organites
Origin of replication (ORI)The site where DNA replication starts.Origine de réplication (ORI)
Osteogenesis imperfectaA condition also known as brittle bone disease; characterized by a triangular shaped face with yellowish brown teeth, short stature and stunted growth, scoliosis, high pitched voice, excessive sweating and loose joints.Ostéogenèse imparfaite
Outbred mouse strainsStrains of mice propagated by nonstandardized matings. These mice retain substantial genetic variability.Souris exogame
PACThe artificial chromosome vector derived from the temperate bacteriophage, P1, used for cloning 100- to 200-kb DNA fragments.PAC
Palindrome, palindromic sequenceIn molecular biology, a nucleotide sequence in which the 5'to 3' sequence of 1 strand of a segment of DNA is the same as that of its complementary strand. The sites of many restriction enzymes are palindromes.Séquence palindromique
ParthenogenesisThe development of an individual from an egg without fertilization.Parthénogenèse
PCRPolymerase chain reaction; a technique for copying the complementary strands of a target DNA molecule simultaneously for a series of cycles until the desired amount is obtained.PCR (polymerase chain reaction)
PedigreeA diagram of the heredity of a particular trait through many generations of a family.Pedigree
PEPAbbreviation for primer extension preamplification.PEP
Peptide fingerprintThe chromatographic pattern of peptides obtained after partial hydrolysis of a protein or peptide. The technique also may be applied to DNA and RNA.Empreinte peptidique
Peptide signalA signal peptide (sometimes referred to as signal sequence, leader sequence or leader peptide) is a short (5-30 amino acids long) peptide present at the N-terminus of the majority of newly synthesized proteins that are destined towards the secretory pathway.Séquence signal
Peroxisomal enzymesEnzymes localized to the peroxisomes. These enzymes are initially synthesized by the free polyribosomes and then enter the cytoplasm and eventually are localized to the peroxisomes. There are at least 40 enzymes. Some are involved in the production and decomposition of hydrogen peroxide and some are concerned with lipid and amino acid metabolism.Enzymes péroxysomales
PeroxisomeA subcellular organelle surrounded by a single membrane containing at least 40 enzymes involved in energy production.Péroxysome
PhenotypeObservable characteristics of an organism produced by the organism's genotype interacting with the environment.Phénotype
Physical mapMap where the distance between markers is the actual distance, such as the number of base pairs.Carte physique
Physical mappingThe determination of the linear positions of genes on a DNA molecule; distances are measured in physical units, i.e., base pairs, kilobases, and megabases.Cartographie physique
PhytohemagglutininLectin isolated from the red bean used to agglutinate red blood cells and stimulate lymphocytes to divide; used in preparation of peripheral blood karyotypes.Phytohémagglutinine
PKUPhenylketonuria, an enzyme deficiency condition characterized by the inability to convert one amino acid, phenylalanine, to another, tyrosine, resulting in mental deficiency. plasmid double-stranded, circular, bacterial DNA into which a fragment of DNA from another organism can be inserted.
Platelet-derived growth factor (PDGF)A protein, produced by platelets and other cells, that strongly stimulates cell growth and division and is involved in normal wound healing. The gene for PDGF is identical to the proto-oncogene sis.Facteur d'augmentation des plaquettes
PleiotropyThe phenomenon of variable phenotypes for a number of distinct and seemingly unrelated phenotypic effects.Pléiotropie
Point mutationA mutation in a single nucleotide.Mutation ponctuelle
PolyadenylationThe addition of approximately 200 adenosine residues at the 3' end of messenger RNAs, apparently involved in their transport of the nucleus and stability.Polyadénylation
Polycystic kidney disease (PKD)A group of conditions characterized by fluid filled sacs that slowly develop in both kidneys, eventually resulting in kidney malfunction.Polykystose rénale
PolymeraseAny enzyme that catalyzes the formation of DNA or RNA from deoxyribonucleotides or ribonucleotides.Polymérase
PolymerasesEnzymes that catalyze the combining of nucleotides to form RNA or DNA (genetic transcription and DNA replication).Polymérases
Polysomes (polyribosomes)Structures composed of multiple ribosomes attached to mRNA in the process of translation.Polysomes
Prader-Willi syndromeA condition characterized by obesity and insatiable appetite, mental deficiency, small genitals, and short stature. May be deletion of #15 chromosome.
PredispositionTo have a tendency or inclination towards something in advance.Syndrome de Prader-Willi
Presymptomatic diagnosisDiagnosis of a genetic condition before the appearance of symptoms.Diagnostique présymptomatique
PrimerNucleotides used in the polymerase chain reaction to initiate DNA synthesis at a particular location.Amorce
ProbabilityThe long term frequency of an event relative to all alternative events, and usually expressed as decimal fraction.Probabilté
ProbandIndividual in a family who brought the family to medical attention.
ProbeSingle-stranded DNA labeled with radioactive isotopes or tagged in other ways for ease in identification.Sonde
PrognosisPrediction of the course and probable outcome of a disease.Pronostique
PronucleusEither of the 2 haploid gamete nuclei just prior to their fusion in the fertilized ovum. Transgenic lines are often generated by microinjection of the transgene into the pronuclear region of these haploid gametes.Pronucleus
ProofreadingThe correction of errors in the nucleotide sequence that can occur during replication, transcription, or translation.Correction des épreuves
Protein suicide mechanismIn dominant disorders, 1 mutant subunit leads to the loss of function of an entire multimeric protein, e.g., collagen.Méchanisme de protéine suicide
Proteus syndromeA condition characterized by distorted asymmetric growth of the body and enlarged head, enlarged feet, multiple nevi on the skin; mode of inheritance is unknown.Syndrome de Protée
Proto-oncogenesNormal genes that are found in normal eukaryotic cells concerned with various aspects of cell division. If amplified, mutated, rearranged, or picked up by a retrovirus, they may give rise to oncogenes that can cause cancer.Proto-oncogènes
Pseudoautosomal regionThe distal tip of the Y chromosome short arm, which undergoes crossover with the distal tip of the X chromosome short arm during meiosis in the male.Région pseudo autosomales
Public policyA set of action guidelines or rules that result from the actions or lack of actions of governmental entities.Politiques publiques
Pulsed field electrophoresisAn electrophoretic technique that allows the separation of relatively long (>5,000 kb) sequences of DNA.Électrophorèse en champs pulsé
Q-bandingThe pattern of bright and dim fluorescent crossbands seen on chromosomes under ultraviolet light after quinacrine mustard staining.Q-banding
QuasidominanceThe pattern of inheritance produced by the mating of an affected homozygote with an individual heterozygous for the same recessive trait so that homozygous affected members appear in 2 or more successive generations.Quasi dominance
R-bandingA chromosome banding technique in which chromosomes are heated in a phosphate buffer; produces dark and light bands in patterns that are the reverse of those produced by G-banding.R-banding
ReceptorA transmembrane or intracellular protein involved in transmission of a cell signal.Récepteur
RecessiveA gene that is phenotypically manifest in the homozygous state but is masked in the presence of a dominant allele.Récessif
Recombinant chromosomeA chromosome in an offspring that has a genotype not found in either parent, due to crossing over in meiosis.Chromosome recombinant
RecombinationThe natural process of breaking and rejoining DNA strands to produce new combinations of genes and, thus, generate genetic variation. Gene crossover during meiosis.Recombinaison
Recombination fractionIn linkage analysis, the fraction of meiotic events that show a recombination between 2 loci.Fraction de recombinaison
Regulatory geneA gene coding for a protein that regulates other genes.Gène de régulation
Repeat sequencesThe length of a nucleotide sequence that is repeated in a tandem cluster.
ReplicationThe identical duplication of DNA.
Replication forkThe unwound region of the DNA double helix in which replication takes place.Fourche de réplication
Replication segregationRefers to changes in the proportions of mitochondrial DNA alleles as the mitochondria reproduce.
Reporter geneA gene used to analyze another gene.Gene rapporteur
Restriction digestThe process in which DNA is exposed to restriction enzymes (restriction endonuclease), causing it to be cleaved into fragments of DNA called restriction fragments.Digestion par enzyme de restriction
Restriction mapA map of a DNA sequence with restriction enzyme recognition sites serving as landmarks.Carte de restriction
Restriction siteA short sequence in DNA that can be recognized and cut by a specific restriction endonuclease.Site de restriction
Retinitis pigmentosaGroup of hereditary ocular disorders with progressive retinal degeneration. Autosomal dominant, autosomal recessive, and x-linked forms.Pigmentation de la rétine
RetinoblastomaA childhood malignant cancer of the retina of the eye. reverse transcriptase viral enzyme used to make cDNA.Rétinoblastome
Reverse geneticsThe application of human gene mapping to clone the gene responsible for a particular disease when no information about the biochemical basis of the disease is available.Génétique inverse
RFLPRestriction fragment length polymorphism; variations occurring within a species in the length of DNA fragments generated by a species endonuclease.Polymorphisme de taille des fragments de restriction
Ribosomal proteinOne of the ribonucleoprotein particles that are the sites of translation.Protéine ribosomale
RibosomesCytoplasmic organelles composed of ribosomal RNA and protein, on which polypeptide synthesis from messenger RNA occurs.Ribosomes
Ring chromosomeA structurally abnormal chromosome in which the end of each chromosome arm has been deleted and the broken arms have reunited to form a ring.Chromosome circulaire
RT-PCRAbbreviation for reverse transcriptase polymerase chain reaction.Amplification en chaîne par polymérisation ou réaction en chaîne par polymérisation
Rubinstein-Taybi syndromeCondition with multiple congenital anomalies including: mental deficiency, broad thumbs, small head, broad nasal bridge and beaked nose.Syndrome de Rubinstein-Taybi
Sanger methodThe enzymatic method for determining the exact nucleotide sequence of a cloned fragment of DNA.Méthode de Sanger
Sanger sequence"plus and minus" or "primed synthesis" method; DNA is synthesized so it is radioactively labeled and the reaction terminates specifically at the position corresponding to a given base.Séquence de Sanger
Satellite DNAA portion of the DNA that differs enough in base composition so that it forms a distinct band on cesium chloride gradient centrifugation; usually contains highly repetitive DNA sequences.ADN stellite
ScaffoldThe nuclear structure observed when histones are experimentally removed from chromosomes. Thought to represent a structural component of the nucleus and of chromosome.Échafaudage
SegregationThe separation of allelic genes at meiosis. Because allelic genes occupy the same locus on homologous chromosomes, they pass to different gametes.Ségrégation
SelectionThe process of determining the relative share allotted individuals of different genotypes in the propagation of a population; the selective effect of a gene can be defined by the probability that carriers of the gene will reproduce.Sélection
Sequence-tagged site (STS)A short fragment of DNA whose exact sequence is found nowhere else in the genome; typically about 200 to 300 bp. Polymerase chain reaction can be used to amplify the known sequences, which can serve as physical landmarks for mapping.
Sex determinationThe mechanism in a given species by which sex is determined; in many species sex is determined at fertilization by the nature of the sperm that fertilizes the egg.
SibshipThe group comprising all the siblings (brothers and sisters) in a family.
Sickle cell anemiaAn hereditary, chronic form of hemolytic anemia characterized by breakdown of the red blood cells; red blood cells undergo a reversible alteration in shape when the oxygen tension of the plasma falls slightly and a sickle-like shape forms.
SilencerThe cis regulatory element that reduces transcription of a gene.Silencieux
Silent geneA mutant gene that has no detectable phenotypic effect.Gène silencieux
Site-directed mutagenesisThe process of creating mutations at specific locations, in contrast to naturally occurring random mutations.Cible de mutagenèse dirigée
Skewed X-inactivationA nonrandom pattern of inactivation of 1 of the X chromosomes in a female that can arise through a variety of mechanisms. When this occurs, the active X chromosome may bear the mutant allele and the female will show signs and symptoms of the disease. The female is called a manifesting heterozygote or a carrier.Inactivation d'un chromosome X
Somatic cell gene therapyThe insertion of new DNA material into a particular tissue of an affected individual in such a way that the inserted DNA does not enter the germline.Thérapie sur cellule somatique
Somatic cell hybridHybrid cell line derived from two different species; contains a complete chromosomal complement of one species and a partial chromosomal complement of the other; human/hamster hybrids grow and divide, losing human chromosomes with each generation until they finally stabilize, the hybrid cell line established is then utilized to detect the presence of genes on the remaining human chromosome.Hybride somatique
Somatic mutationA mutation occurring in any cell that is not destined to become a germ cell; if the mutant cell continues to divide, the individual will come to contain a patch of tissue of genotype different from the cells of the rest of the body.Mutation somatique
Southern blottingA technique for transferring electrophoretically resolved DNA segments from an agarose gel to a nitrocellulose filter paper sheet via capillary action; the DNA segment of interest is probed with a radioactive, complementary nucleic acid, and its position is determined by autoradiography.Transfert d'ADN par Southern blot
Spina bifidaA congenital condition that results from altered fetal development of the spinal cord, part of the neural plate fails to join together and bone and muscle are unable to grow over this open section.Spina bifida
SSCPAbbreviation for single-strand conformation polymorphism.Polymorphisme de conformation des simples brins (SSCP)
SSPAbbreviation for sequence-specific primer. These are used in PCR reactions.Séquence spécifique d'amorce
STRAbbreviation for short tandem repeat. These often serve as polymorphic markers.
STRPAbbreviation for short tandem repeat polymorphism.
STSSee sequence-tagged site.
SyndromeA recognizable pattern or group of multiple signs, symptoms or malformations that characterize a particular condition; syndromes are thought to arise from a common origin and result from more than one developmental error during fetal growth.
SyngeneicRefers to genetically identical members of the same species.
Tay-Sachs diseaseA fatal degenerative disease of the nervous system due to a deficiency of hexosamidase A, causing mental deficiency, paralysis, mental deterioration, and blindness; found primarily but not exclusively among Ashkenazi Jews. Autosomal recessive.Maladie de Tay-Sachs
TeratogensAny agent that raises the incidence of congenital malformations.Tératogènes
TraitAny detectable phenotypic property of an organism.Caractère
Transcript mapA genetic map in which expressed sequences, e.g., mRNAs, mRNA transcripts, corresponding to genes are mapped; a functional blueprint of the genome.Carte transcriptomique
TranscriptionThe formation of an RNA molecule upon a DNA template by complementary base pairing.Transcription
TransductionThe transfer of bacterial genetic material from one bacterium to another using a phage as a vector.Transduction
TransferaseEnzymes that catalyze the transfer of functional groups between donor and acceptor molecules.Transférase
Transforming retrovirusA retrovirus carrying an additional DNA sequence (often an oncogene) that confers the ability to transform infected cells to malignant phenotype.Retrovirus vecteur de transformation
TransgeneA foreign gene; typically, a gene produced by recombinant DNA techniques.Transgène
Transgenic organismOne into which a cloned genetic material has been experimentally transferred, a subset of these foreign gene express themselves in their offspring.Turner syndrome a chromosomal condition in females (usually 45,XO) due to monosomy of the X- chromosome; characterized by short stature, failure to develop secondary sex characteristics, and infertility.Organisme trans génique
TranslationThe formation of a polypeptide chain in the specific amino acid sequence directed by the genetic information carried by mRNA.Translation
TranslocationA chromosome aberration which results in a change in position of a chromosomal segment within the genome, but does not change the total number of genes present.Translocation
Transposable elementA DNA sequence that can move from one chromosomal location to another.Élément transposable (transposon)
TransversionA mutation in which purine is substituted for pyrimidine or vice versa.Transversion
TripletA sequence of 3 nucleotides comprising a codon of a nucleic acid and representing the code for an amino acid (triplet code, codon).Triplette
Triplet codeA code in which a given amino acid is specified by a set of three nucleotides.Code triplet
Tumor suppressor geneGenes that normally function to restrain the growth of tumors; the best understood case is for hereditary retinoblastoma.Gène supresseur de tumeur
Tumor-suppresser geneA gene thought to suppress formation of tumors; loss of suppression leads to malignant transformation. P53 is an example of a tumor-suppresser gene.Gène supresseur de tumeur
Unequal crossing overCrossing over between similar DNA sequences that are misaligned, resulting in sequences with deletion or duplication of DNA segments. A cause of a number of genetic variants, e.g., -thalassemia and Lepore hemoglobin.Enjambement inégal
UNESCOUnited National Educational, Scientific, and Cultural Organization.UNESCO
Variable expressivityRefers to the variable severity of a genetic trait. Individuals with the same mutant gene with pleiotropic effects frequently show variable expressivity due to either environmental effects or effects of other genes modifying the expression of the mutant gene.Expression variable
VectorA self-replicating DNA molecule that transfers a DNA segment between host cells.Vecteur
VNTRVariable number tandem repeats; any gene whose alleles contain different numbers of tandemly repeated oligonucleotide sequences.VNTR
Von Hippel-Lindau syndromeAn autosomal dominant condition characterized by the anomalous growth and proliferation of blood vessels on the retina of the eye and the cerebellum of the brain; cysts and cancers in the kidneys, pancreas, and adrenal glands.Maladie de von Hippel-Lindau
Western blotting analysisA technique used to identify a specific protein; the probe is a radioactively labeled antibody raised against the protein in question.Buvardage de western
Wild typeThe term used to indicate the normal allele (often symbolized as +) or the normal phenotype.Type sauvage
X-autosome translocationThe reciprocal translocation between the X chromosome and 1 of the autosomes.Translocation entre X et un autosome
X-inactivationThe repression of one of the two X-chromosomes in the somatic cells of females as a method of dosage compensation; at an early embryonic stage in the normal female, one of the two X-chromosomes undergoes inactivation, apparently at random, from this point on all descendent cells will have the same X-chromosome inactivated as the cell from which they arose, thus a female is a mosaic composed of two types of cells, one which expresses only the paternal X-chromosome, and another which expresses only the maternal X-chromosome.Inactivation du chromosome X
X-linked dominantA trait that is manifested in the heterozygous female as well as in the male who has the mutant allele on 1 of the X chromosomes.Caractère lié au chromosome X dominant
X-linked recessiveA disorder manifested exclusively in a male who is a heterozygote or a homozygous female when the abnormal gene is carried on the X chromosome. A female is usually a carrier if she is heterozygous and transmits the disease to the son.Caractère lié au chromosome X récessif
XYY syndromeGenetic condition in males with extra Y chromosome (in 1 in 1000 male births). Symptoms: tall stature (over 6'), may including sterility, developmental delay, learning problems.Syndrome 47,XYY
YACYeast artificial chromosome; a linear vector into which a large fragment of DNA can be inserted; the development of YAC's in 1987 has increased the number of nucleotides which can be cloned.Chromosomes artificiels de levure
Zinc finger proteinsTranscription-activator proteins containing finger-like structures containing zinc atoms.Protéines doigts de zinc
Zoo blotA Southern blot containing conserved DNA sequences from related genes of different species. It is taken as evidence that the sequences are coding sequences from a specific gene.Zoo blot
Zoo blotNorthern analysis of mRNA from different organisms.Zoo blot