Deletion of exons 1-5 of the STS gene causing X-linked ichthyosis.
X-linked ichthyosis is an inherited disorder due to steroid sulfatase deficiency. It is clinically characterized by dark, adhesive, and regular scales of the skin. Most X-linked ichthyosis patients present large deletions of the STS gene and flanking markers; a minority show a point mutation or partial deletion of the STS gene. In this study we analyzed the STS gene in a family with simultaneous occurrence of X-linked ichthyosis and ichthyosis vulgaris. X-linked ichthyosis diagnosis was confirmed through steroid sulfatase assay in leukocytes using 7-[3H]-dehydroepiandrosterone sulfate as a substrate. Exons 1, 2, 5, and 6-10, and the 5' flanking markers DXS1130, DXS1139, and DXS996 of the STS gene were analyzed by polymerase chain reaction. X-linked ichthyosis patients of the family (n = 4 males) had undetectable levels of STS activity (0.00 pmol per mg protein per h). The DNA analysis showed that only exons 6-10 and the 5' flanking markers of the STS gene were present. We report the first partial deletion of the STS gene spanning exons 1-5 in X-linked ichthyosis patients.
Valdes-Flores
M
M
Servicio de Genetica, Instituto Nacional de Ortopedia and Servicio de Genetica, Hospital General de Mexico, Facultad de Medicina, UNAM, Mexico D.F., Mexico.
Kofman-Alfaro
S H
SH
Vaca
A L
AL
Cuevas-Covarrubias
S A
SA
D001192:Arylsulfatases / Q000235:genetics*; D005091:Exons / Q000235:genetics*; D017353:Gene Deletion; D006801:Humans; D016112:Ichthyosis Vulgaris / Q000150:complications; D016114:Ichthyosis, X-Linked / Q000150:complications / Q000235:genetics*; D008297:Male; D043266:Steryl-Sulfatase
D001192:Arylsulfatases; D043266:Steryl-Sulfatase