The identification of X-linked mental retardation genes (XLMR) represents a challenge of considerable medical importance, given the reported high cumulative frequency of this heterogenous disorder, estimated at approximately 1/600 male births. Whereas pooling families is useful to fine-map genetic l
X-linked nonspecific mental retardation (MRX16) mapping to distal Xq28: Linkage study and neuropsychological data in a large family
β Scribed by Gendrot, Chantal; Ronce, Nathalie; Raynaud, Martine; Ayrault, Anne-Dominique; Dourlens, Juliette; Castelnau, Pierre; Muh, Jean-Pierre; Chelly, Jamel; Moraine, Claude
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 94 KB
- Volume
- 83
- Category
- Article
- ISSN
- 0148-7299
- DOI
- 10.1002/(sici)1096-8628(19990423)83:5<411::aid-ajmg14>3.0.co;2-b
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β¦ Synopsis
A genetic linkage study was performed on a large four-generation family with variable nonspecific X-linked mental retardation (MRX16), speech abnormalities, and retardation of all milestones. Significant linkage was found in the Xq28 region with loci DXS52, DXS15, BGN, and DXS1108 with maximum LOD scores of 4.86, 4.01, 4.83, and 5.43, respectively, at = 0.00. Recombination was observed at the locus DXS1113, thus mapping the gene in an 8-Mb interval between this marker and the Xq telomere. Linkage intervals of three other MRX families overlap with this interval in Xq28 where the RABGDIA gene, mutated in the MRX41 and MRX48 families, is also located. In MRX3, MRX28, but also in MRX16, no alteration of RABGDIA has been found, thus suggesting the existence of at least two MRX genes in distal Xq28.
π SIMILAR VOLUMES
Four families are described in which mental retardation segregates in an X-linked fashion. Mental retardation was the only consistent clinical finding in all affected males. The degree of retardation varied from mild to profound both between and within families. Linkage analysis localized the geneti
We describe a large family with nonspecific X-linked mental retardation (MRX 47). An X-linked recessive transmission is suggested by the inheritance from the mothers in two generations of a moderate to severe form of mental retardation in six males, without any specific clinical findings. Two point
X-linked mental retardation (XLMR) includes distinct entities in which mental deficiency is either associated with specific abnormalities (syndromal) or not (nonsyndromal). We report on the clinical, neuropsychological, and laboratory findings and linkage analysis in one family with XLMR and isolate
Of the gene-rich regions of the human genome, Xq28 is the most densely mapped. Mutations of genes in this band are responsible for 10 syndromal forms of mental retardation and 5 nonsyndromal forms. Clinical and molecular studies reported here add an additional syndromic form of X-linked mental retar
An Austrian family with nonsyndromic Xlinked mental retardation (MRX) is reported in which the obligatory carrier females are normal, and 5 affected males have mild to moderate mental retardation. Linkage analysis indicated an X pericentromeric localization, with flanking markers DXS989 and DXS1111