ANGIOKERATOMA CORPORIS DIFFUSUM ASSOCIATED WITH BETA-MANNOSIDASE DEFICIENCY

Background: Angiokeratoma corporis diffusum (ACD) was at one time thou ght to be synonymous with Anderson-Fabry disease. However, it is well known that widespread angiokeratomas may also be found in other lysoso mal enzyme disorders, as well as in patients with normal enzyme activi ties. beta-Mannosidase deficiency was first described in humans in 198 6; since then, only 11 cases of beta-mannosidase deficiency, which occ urred in 8 families, have been reported. Although the clinical manifes tations are varied, mental retardation and neurologic disorders are pr esent in practically all patients. Observations: We describe a 22-year -old woman who, since the age of 12 years, presented with progressive ACD affecting the lower limbs and the buttocks. Enzymatic studies reve aled beta-mannosidase deficiency in cultured fibroblasts and in sample s of serum and leukocytes. The patient's parents in turn exhibited int ermediate enzyme levels, thus confirming the recessive autosomal hered itary nature of the disease. With the exception of an introverted char acter, the patient demonstrated no other anomalies. Conclusions: This is the first case of beta-mannosidase deficiency diagnosed as a result of purely dermatologic findings, in the form of ACD. beta-Mannosidase deficiency should therefore be included when screening for enzyme abn ormalities in patients with ACD, even in the absence of neurologic dis orders or mental retardation.