Pseudoxanthoma elasticum.

Pseudoxanthoma elasticum is an incurable, autosomal-recessive, genetic disorder that is caused by mutations in the ABCC6 gene. It is characterized by progressive mineralization and fragmentation of the elastic fibers in the skin, retina, and blood vessels. The characteristic cutaneous features bring the patient to medical attention, but morbidity is related to the degree of extracutaneous involvement. The disease is progressive with phenotypic variability and no definite genotype-phenotype correlation. Treatment is supportive and is directed at prevention and early detection of adverse ocular and cardiovascular sequelae. We present two siblings with pseudoxanthoma elasticum, who have considerable differences in disease related morbidity, which highlights intra-familiar phenotypic heterogeneity.