Mapping of a new SGBS locus to chromosome Xp22 in a family with a severe form of Simpson-Golabi-Behmel syndrome

Mapping of a new Simpson-Golabi-Behmel syndrome (SGBS) locus to chromosome Xp22 has been carried out in a family with a severe form of the syndrome an X-linked overgrowth syndrome with visceral/skeletal abnormalities associated. Not all of those with SGBS have demonstrated disruptions of the glypican-3 gene (GPB3) locus. Alterations in this gene, located on Xq26, are implicated in etiology of the more mild forms of the disorder. A second SGBS locus is on Xp22. The mapping project used 25 simple tandem-repeat polymorphism markers all across the X chromosome.