Ichthyosis: the skin manifestation of multiple sulfatase deficiency

Juvenile sulfatidosis (Austin type) or multiple sulfatase deficiency is an extremely rare autosomal recessive disorder affecting the activity of many sulfatases: arylsulfatase A, several mucopolysaccharide sulfatases, and steroid sulfatase. Certain aspects of the clinical phenotype can be attributed mainly to a deficiency of one specific sulfatase. Most patients develop metachromatic leukodystrophy caused by arylsulfatase A deficiency, dysostosis multiplex by mucopolysaccharide sulfatase deficiency, and ichthyotic skin by steroid sulfatase deficiency. We describe a 7-year-old boy with developmental delay from 7 months of age, progressive spastic quadriparesis, and coarse facial features. By 27 months of age, an ichthyotic rash had developed on the limbs, trunk, and scalp. A skin biopsy specimen revealed hyperkeratosis with a normal granular layer. The diagnosis of multiple sulfatase deficiency was demonstrated by measuring sulfatase activities in fresh leukocytes: there were large deficiencies of arylsulfatase A and B plus reduced arylsulfatase C. The ichthyosis associated with multiple sulfatase deficiency has an autosomal recessive inheritance, is caused by steroid sulfatase deficiency, and the scaling is sometimes milder than in X-linked recessive ichthyosis. This could reflect the residual activity of steroid sulfatase in some cases.