title: Down syndrome genetics: unravelling a multifactorial disorder.
abstract: Down syndrome is a common disorder affecting many tissues both during development and later on in adult life; the principle feature of all cases is a specific form of mental retardation, which is combined with a range of variable traits. Down syndrome is an aneuploidy syndrome that is caused by trisomy for human chromosome 21. While the phenotype is most likely due to a subtle increase in gene dosage of only a small minority of the estimated 500-800 genes that are present on this chromosome, the molecular genetics of Down syndrome remains speculative. However, recent advances on a number of fronts, including chromosome studies, gene identification and mouse modelling, are giving us the tools to dissect this multifactorial gene dosage disorder.
authors.affiliation: Department of Biochemistry and Molecular Genetics, Imperial College School of Medicine at St. Mary's, London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Hernandez
authors.forename: E M
authors.initials: EM
authors.lastname: Fisher
mesh_terms: D000818:Animals; D002869:Chromosome Aberrations; D002891:Chromosomes, Human, Pair 21; D004195:Disease Models, Animal; D004314:Down Syndrome / Q000235:genetics*; D005544:Forecasting; D015870:Gene Expression; D016045:Human Genome Project; D006801:Humans; D051379:Mice; D010641:Phenotype