Angiokeratoma corporis diffusum (Anderson-Fabry disease) in a single large family in Nova Scotia.

Eighteen males, 17 of whom were members of a single family, affected with angiokeratoma corporis diffusum were examined in detail to determine the extent of clinical variation of the expression of what was almost certainly the same X-linked mutation in each. The commonest symptom was episodic bouts of severe, painful dysaesthesia in hands and feet. This was a major complaint of 12, a minor complaint of 5, and absent in 1. In over half the subjects, the skin rash that is considered a characteristic sign of the disease was absent or inconspicuous. All exhibited mild clubbing of fingers and toes, and 15 showed variable limitation of active and passive extension of the 5th fingers bilaterally. Only 2 (age 36 and 47) had evidence of significant renal disease. Electrocardiograms showed abnormally short PR intervals in 4, and right ventricular conduction disturbances in 5. Echocardiograms on 9 showed no evidence of myocardial dysfunction. The marked variation of the expression of some features of the disease indicates that the clinical expression of the mutation is likely to be subject to considerable genetic or environmental modification in each individual.