Atypical X-linked ichthyosis in a patient with a large deletion involving the steroid sulfatase (STS) gene.

A 70-year-old male presented with very large, thick, tightly adherent, dark-brown scales on the front of his lower extremities. His face, neck, back, abdomen, upper extremities, flexural areas, palms and soles as well as hair and nails were not involved. Family history was negative for similar lesions. Otherwise, the patient had a normal development. Onset of symptoms occurred during childhood with scales on lower extremities with no more additional features. Treatment included emollients exclusively with partial and temporary remission of cutaneous lesions. Recently, the patient had not received topical or systemic medical treatment. Laboratory investigations were within normal limits. The patient had undetectable levels of STS activity when compared with normal control (0.00 pmol mg(-1) protein h(-1)) which confirmed the diagnosis of X-linked ichthyosis (XLI) . PCR analysis showed deletion of the STS gene, markers DXS1139 and DXF22S1and the 5' end of the VCX3A gene. The patient had scales present on lower extremities only with no medical treatment that corresponded to an unusual clinical manifestation of XLI. Clinical manifestations of XLI are due to a great variety of environmental, genetic and individual factors that should be considered in XLI diagnosis.