Localization of the gene for X-linked calvarial hyperostosis to chromosome Xq27.3-Xqter

To date, only one family has been described with X-linked calvarial hyperostosis including three affected individuals. In order to localize the disease causing gene, 31 polymorphic microsatellite markers that spread across the X-chromosome were analyzed. Genotypes were combined in haplotypes to delineate the region. A chromosomal region spanning from Xq27.3 to Xqter cosegregates with the disorder. This region encompasses 23.53 cM or 8.2 Mb according to the deCODE map and contains 165 genes. CNV-analysis did not show small duplications or deletions in this region. Exome sequencing was performed on a male patient in this family. However, this did not reveal any putative mutation. These results indicate that a non-coding regulatory sequence might be involved in the pathogenesis of this disorder.