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Educational Items Section Short Communication Atlas of Genetics and Cytogenetics in Oncology and Haematology OPEN ACCESS JOURNAL AT INIST-CNRS Educational Items Section Short Communication Glossary of Medical and Molecular Genetics Louis Dallaire Centre de Recherche, Hôpital Ste-Justine, Montréal, Canada (LD) Published in Atlas Database: November 2004 Online updated version : http://AtlasGeneticsOncology.org/Educ/GlossaryID30028ES.html DOI: 10.4267/2042/38176 This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 France Licence. © 2005 Atlas of Genetics and Cytogenetics in Oncology and Haematology This French / English glossary of medical and molecular genetics is intended for students in human and biological sciences as well as medical and para-medical personnel. It is mainly a tool for teaching and research. This glossary contains terminology frequently used in clinics and the laboratory. Within all areas of genetics the utilisation of terms in the glossary may also evolve with time or develop specific conations in different areas of study. There is no direct correspondence between the French and English terms defined in these glossaries. Certain terms exist in only one of these languages. Also the utilisation of a given term may differ to some extent between French and English. The definitions of terms common to both glossaries are not necessarily literal translations of one another. Suggestions, corrections as well as the addition of new terms are welcomed. We are grateful to the authors of those references who have contributed to the preparation of this glossary. membrane filters for detection of specific base A sequences by radio-labelled complementary probes. Acardia (French: acardia) Congenital absence of the Advanced maternal age, AMA (French: âge maternel heart. avancé, AMA) In most prenatal diagnostic clinics 35 Acellular system , see: system acellular. years of age and more is considered as advanced Acentric (French: acentrique) Absence of centromere maternal age due to the increased risk of chromosomal in a chromosome structure. non disjunction in the foetus. Achondrogenesis (French: achondrogénèse) Affinity chromatography (French: chromatographie Example of bone dysplasia due to a mutation in a d’affinité) Any form of chromatography in which the collagen gene, COL2A1. Skeletal malformations are components of the sample are separated on the basis of seen at ultrasound during the second trimester of chemical affinity for a substance such as a binding pregnancy. protein or an immunoglobulin. Acrocentric (French: acrocentrique) Position of the AFP, alpha foetoprotein (French: AFP, centromere near the end of a chromosome. alphafoetoprotéine) Specific foetoglobulin synthesized Chromosomes 13-15 and 21,22 in man are acrocentric. by the liver and secreted in foetal serum during the Adaptor (French: adapteur) Short nucleotidic foetal life and the neonatal period. An open spinal sequence that has the property to link two DNA defect in the fetus is usually accompaniedby an fragments that hat have no terminal complementary increase in AFP in the amniotic fluid and a transudation sequences. towards the maternal circulation. AFP measurements in amniotic fluid and maternal serum are used in prenatal Adenine (French: adénine) A nitrogenous base, one diagnosis of genetic diseases. member of the base pair A-T, adenine- thymine. Agenesis (French: agénésie) Absence of an organ or ADN transfer, Southern blotting (French: structure. marquage Southern) Transfer by absorption of DNA fragments separated in electrophoretic gels to Atlas Genet Cytogenet Oncol Haematol. 2005; 9(1) 92 Glossary of Medical and Molecular Genetics Dallaire L (French: allèle) Alternative forms of a genetic locus; a normal modal number, is considered a deviation from single allele for each locus is inherited separately from the 2n ratio. each parent. Example: at a locus for eye colour the Angelman syndrome (French: Angelman, syndrome allele might result in blue or brown eyes. de) Angelman and Prader Willi syndromes are Allelic frequencies (French: fréquences alléliques) examples of syndromes related to parental imprinting. Frequencies of allelic genes. Both syndromes include mental retardation and clinical anomalies. They are due to the loss of a segment of Allelomorph gene , see: alleles. chromosome 15 located in the proximal region of the Allotransplant (French: allotransplant) Organ or long arm, 15q11q13. Depending on the parental origin tissue transplant between two individuals. of chromosome 15 and the exact location of the Alpha foetoprotein , see AFP. chromosomal anomaly, two different syndromes are Alu sequences (French: séquences ALU) DNA identified. segments of approximately 300 base pairs with similar Annealing (French: annelage) Hybridization of a sequences. There are 50,000 copies in the human synthetic oligonucleotide to a single strand nucleic genome. They have a reconnaissance site for the ALU acid. It is how a specific nucleotide sequence can be restriction enzyme. identified. AMA , see advanced maternal age. Anophtalmia (French: anophtalmie) Congenital Amino acid (French: acide aminé) Any of a class of absence of eye. 20 molecules that are combined to form proteins in Anthelix (French: anthélix) Proximal fold of the living things. The sequence of amino acids in a protein external ear. and hence protein function are determined by the Antibody (French: anticorps) A specific substance genetic code. produced by man, and animal, as a reaction to the Amniocentesis (French: amniocentèse) presence of an antigen. Transabdominal or transuterine aspiration of amniotic Anticipation (French: anticipation) Phenomenon in fluid usually performed during the second trimester of which the severity of the condition seems to increase or pregnancy, for instance in the process of prenatal occur at an earlier age in subsequent generations. diagnosis of a genetic disease. Anticodon (French: anticodon) Group of three Amplifiable plasmid (French: plasmide amplifiable) nucleotides located at one end of the transfer tRNA and Plasmid that continues to replicate even when host cell by which it adapts, to the corresponding codon of the multiplication is blocked. messenger mRNA, to fix the amino acid it carries. Amplification (French: amplification) An increase in Antigen (French: antigène) A substance which has the the number of copies of a specific DNA fragment; can power of inducing, in man or in an animal, the take place in vivo or in vitro. See cloning, polymerase formation of antibodies. chain reaction. Antisense strand (French: brin anti-sens) Nucleic Amplification, DNA (French: amplification d’ADN) acid that has a sequence exactly opposite to a mRNA In vivo or in vitro increase in the number of a specific molecule made by the body; it binds to the mRNA DNA fragments. molecule to prevent a protein from being made. Amplification gene (French: amplification de gène) Apoptosis (French: apoptose) Programmed cell The increase in number of those genes needed for death. specialized functions in certain differentiated cells. Arachnodactyly (French: arachnodactylie) Long and Analogue base (French: base analogue) Molecule thin finger(s). which can replace a structure similar to nitrogenous Arhinencephaly (French: arhinencéphalie) Absence DNA or RNA bases. Example : 5-bromo-uracil is a of mid-brain structure. mutagenic analogue. Arrayed library (French: banque de gènes) Individual Anaphase (French: anaphase) Stage in and the first primary recombinant clones (hosted in phage, cosmid, and second following the metaphase, during which the YAC, or other vector) that are placed in two- centromere splits and the chromatids which were lined dimensional arrays inmicrotiter dishes. Each primary up on the spindle begin to move apart towards opposite clone can be identified by the identity of the plate and poles of the spindle. the clone location (row and column) on that plate. Anencephaly (French: anencéphalie) Absence of Arrayed libraries of clones can be used for many cranial bone structure usually accompanied by a severe applications, including screening for a specific gene or brain defect. genomic region of interest as well as for physical Aneuploidy (French: aneuploïdie) Situation when one mapping. Information gathered on individual clones or more chromosomes, missing or in excess of the from various genetic linkage and physical map analyses Atlas Genet Cytogenet Oncol Haematol. 2005; 9(1) 93 Glossary of Medical and Molecular Genetics Dallaire L is entered into a relational database and used to construct physical and genetic linkage maps B simultaneously; clone identifiers serve to interrelate the BAC, bacterial artificial chromosome (French: multilevel maps. chromosome bactérien artificiel, BAC) A vector used Artificial gene (French: gène artificiel) A double- to clone DNA fragments of 100 to 300 kb insert size, stranded DNA molecule, carrying a specific sequence, average of 150 kb in Escherichia coli cells. Based on that will code for a specific amino acid sequence and the naturally occurring F-factor plasmid found in the that has been produced in vitro. bacterium Escherichia coli. Ascites (French: ascite) Accumulation of fluid in the Back mutation (French: réversion vraie). abdominal cavity. Bacteriophage (French: bactériophage), see phage. Asymmetrical division (French: division Balanced translocation (French: translocation asymétrique) Unequal segregation of chromosomes in équilibrée) transposisiton of chromosomal segments mitosis. It leads to two daughter cells that have a without
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