title: Localization of a non-syndromic X-linked mental retardation gene (MRX80) to Xq22-q24.
abstract: Isolated mental retardation is clinically and genetically heterogenous and may be inherited in an autosomal dominant, autosomal recessive, or X-linked manner. We report here a linkage analysis in a large family including 15 members, 6 of whom presenting X-linked non-syndromic mental retardation (MRX). Two-point linkage analysis using 23 polymorphic markers covering the entire X chromosome demonstrated significant linkage between the causative gene and DXS8055 with a maximum LOD score of 2.98 at theta = 0.00. Haplotype analysis indicated location for the disease gene in a 23.1 cM interval between DXS1106 and DXS8067. This MRX localization overlaps with 7 XLMR loci (MRX23, MRX27, MRX30, MRX35, MRX47, MRX53, and MRX63). This interval contains two genes associated with non-syndromic mental retardation (NSMR), namely the PAK3 gene, encoding a p21-activated kinase (MRX30 and MRX47) and the FACL4 gene encoding a fatty acyl-CoA ligase (MRX63). As skewed X-inactivation, an apparently constant feature in FACL4 carrier females was not observed in an obligate carrier belonging to the MRX family presented here, the PAK3 gene should be considered as the strongest candidate for this MRX locus.
authors.affiliation: Center for Molecular and Cellular Genetics, University Lyon I, Villeurbanne, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Verot
authors.forename: Nicole
authors.initials: N
authors.lastname: Alloisio
authors.forename: Laurette
authors.initials: L
authors.lastname: Morlé
authors.forename: Muriel
authors.initials: M
authors.lastname: Bozon
authors.forename: Renaud
authors.initials: R
authors.lastname: Touraine
authors.forename: Henri
authors.initials: H
authors.lastname: Plauchu
authors.forename: Patrick
authors.initials: P
authors.lastname: Edery
mesh_terms: D002874:Chromosome Mapping; D041321:Chromosomes, Human, X; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D038901:X-Linked Intellectual Disability / Q000235:genetics*; D010375:Pedigree