A novel partial deletion of exons 2-10 of the STS gene in recessive X-linked ichthyosis

X-linked ichthyosis is an inherited disease due to steroid sulfatase defici ency. Onset is at birth or early after birth with dark, regular, and adhere nt scales of skin. Approximately 85%-90% of X-linked ichthyosis patients ha ve large deletions of the STS gene and flanking sequences. Three patients h ave been identified with partial deletions of the gene. Two deletions have been found at the 3' extreme and the other one implicating exons 2-5. This study describes a novel partial deletion of the STS gene in an X-linked ich thyosis patient. The subject was classified through steroid sulfatase assay in leukocytes using 7-[H-3]-dehydroepiandrosterone sulfate as a substrate. Exons 1, 2, 5, and 7-10, and 3' flanking sequences DXS1131, DXS1133, DXS23 7, DXS1132, DXF22S1, and DXS278 of the STS gene were analyzed through polym erase chain reaction. The DNA analysis showed that exon 1 and 3' flanking s equences from DXS237 to DXS278 were present. In this study we report the fo urth partial deletion of the STS gene and the first spanning exons 2-10 in X-linked ichthyosis patients.