Linkage mapping of a new syndromic form of X-linked mental retardation, MRXS7, associated with obesity

A new syndromic form of X-linked mental retardation associated to obesity, MRXS7, has been localised to Xp11.3-Xq23 in a large Pakistani family. The t en affected males show clinical manifestations of mental retardation, obesi ty and hypogonadism. The family was genotyped by a set of microsatellite ma rkers spaced at approximately 10 cM intervals on the X chromosome. Linkage to five adjacent microsatellite markers, mapping in the pericentromeric are a, was established and a maximum two-point lod score of 3.86 was reached at zero recombination with marker DXS1106. Reduced recombination events aroun d the centromere prevented precise mapping of the gene.