ABSTRACT
We report a new polymorphic DNA marker (pJH89, DXS539) proximal to the fragile-X site. The pJH89 probe identifies a TaqI and a NcoI restriction fragment length polymorphism (combined heterozygosity of 42%) and is linked to the fragile-X locus with a maximal LOD score of 12 at 4 cM. Multipoint linkage analysis and physical mapping studies indicate that the pJH89 probe is located within in the interval defined by the markers DXS369 and DXS548.
Subject(s)
Chromosome Fragility , Fragile X Syndrome/genetics , Genetic Linkage/genetics , Polymorphism, Genetic/genetics , Female , Genetic Markers , Humans , Lod Score , MaleABSTRACT
The gene for nephrogenic diabetes insipidus (DIR) and the vasopressin type 2 receptor gene (AVPR2) have both been localized in the Xqter region by genetic mapping and functional expression studies, respectively. In this paper genetic evidence that the DIR locus is localized distal to the DXS305 locus and that the functional gene for the V2 receptor is localized between the markers DXS269 and F8 is presented. These further refinements in the localization of both genes strengthen the assumption that both genes are identical and provide a rationale for cloning the gene by reversed genetics strategies.
