title: [Mental retardation linked to fragility of chromosome X: current knowledge].
abstract: The association of the fragile X chromosome with X-linked mental retardation is now well established. The main clinical features are mental retardation, typical facial dysmorphism and macroorchidism. Cytogenetically there is a fragile site in band Xq27-28 which can be demonstrated using specific techniques. The genetic studies are compatible with a X-linked dominant inheritance with an incomplete penetrance. A preliminary estimation of an overall frequency of 1: 2000 males for the fra(X)(q) condition is suggested.
mesh_terms: D001973:Bromodeoxyuridine / Q000494:pharmacology; D002648:Child; D002871:Chromosome Banding; D004431:Ear, External / Q000002:abnormalities; D005145:Face / Q000002:abnormalities; D005467:Floxuridine / Q000494:pharmacology; D005492:Folic Acid / Q000494:pharmacology; D005600:Fragile X Syndrome / Q000175:diagnosis / Q000235:genetics*; D005787:Gene Frequency; D008040:Genetic Linkage; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008214:Lymphocytes / Q000032:analysis; D008297:Male; D010375:Pedigree; D011296:Prenatal Diagnosis; D012729:Sex Chromosome Aberrations / Q000235:genetics*
chemical_list: D005467:Floxuridine; D005492:Folic Acid; D005954:Glucosephosphate Dehydrogenase; D001973:Bromodeoxyuridine
vernacular_title: Le retard mental lié à la fragilité du chromosome X: connaissances actuelles.