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Ichthyosis, X-linked, Microdeletion Xp22.31

Steroidsulfatase deficiency

Clinical Features

The typical feature of X-linked ichthyosis (hyperkeratosis) is a massive scaling on the extremities, the trunk and the neck. The epidermis is dysfunctional due to a deficiency of the enzyme steroid sulfatase (STS).

Genetic Information

A microdeletion in the short arm of the X chromosome (Xp22.3) in males leads to a deficiency of the gene coding for steroid sulfatase. 85% of the patients exhibit a gross deletion in this region of the STS gene, in 15% of the cases there are point mutations or very large deletions involving additional genes (e. g. Kallmann gene).

Prevalence

1 : 2 000 to 1 : 6 000

Diagnostic