Heterogeneity of pseudoxanthoma elasticum: delineation of a new form?

Sixty-four patients with pseudoxanthoma elasticum (PXE) were investigated in a nationwide study within South Africa and Zimbabwe. Thirty-nine individuals formed a distinct clinical subgroup. These persons were found exclusively among people of Afrikaner descent, whose origins are mainly derived from Dutch and French-Huguenot stock. This disorder was inherited as an autosomal recessive trait and presented mild to moderate cutaneous and cardiovascular manifestations. However, after the third decade of life severe visual impairment developed and culminated in blindness in 8 people by the age of 50. The cause of the visual defect was progressive extension of angioid streaks into the macula with neovascularization and haemorrhage. Laser therapy may have prevented further bleeding in 4 instances. The severity of ocular involvement contrasted with the mildness of the skin changes, and in this respect the condition seems to differ from previously delineated autosomal recessive forms of PXE.