title: Linkage of nonspecific X-linked mental retardation to Xq21.31.
abstract: Mental retardation unassociated with the Fragile X syndrome accounts for up to 60% of patients with X-linked mental retardation. In this investigation, we report on a family with mild non-specific X-linked mental retardation (MRX) without other apparent phenotypic abnormalities. Linkage analysis on 27 relatives using 18 polymorphic markers spanning the X-chromosome demonstrated close linkage to DXYS1 with a peak LOD score of 2.14 at a theta of 0. Numerous families with various types of MRX have now been studied by other investigators using molecular genetic techniques. In addition to the family described in this report, a number of these have demonstrated linkage to the DXYS1 locus. These data suggest that a gene for mental retardation may exist in the region of DXYS1. Alternatively, this area of the X-chromosome may harbor multiple different but closely linked genes which cause the various types of MRX.
authors.affiliation: Department of Medical Genetics, Mayo Clinic and Foundation, Rochester, MN 55905.
authors.forename: K B
authors.initials: KB
authors.lastname: Jedele
authors.forename: V V
authors.initials: VV
authors.lastname: Michels
authors.forename: D J
authors.initials: DJ
authors.lastname: Schaid
authors.forename: K V
authors.initials: KV
authors.lastname: Schowalter
authors.forename: S N
authors.initials: SN
authors.lastname: Thibodeau
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002874:Chromosome Mapping; D015342:DNA Probes; D005260:Female; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008126:Lod Score; D008297:Male; D010375:Pedigree; D014960:X Chromosome
chemical_list: D015342:DNA Probes; D005819:Genetic Markers