Calcification of elastic fibers in pseudoxanthoma elasticum.

Pseudoxanthoma elasticum is an inherited disorder of connective tissue that is characterized by calcification of elastic fibers with associated abnormalities of the skin, ocular, and cardiovascular systems. The genetic defect causing pseudoxanthoma elasticum has not been determined and the diagnosis relies on clinical recognition of skin lesions and histologic demonstration of calcification of elastic fibers that are clumped and fragmented in the dermis. The role of connective tissue components in the etiology of pseudoxanthoma elasticum is reviewed and includes changes in collagen, elastin, glycosaminoglycans, fibronectin, microfibrillar proteins, modifying enzymes of extracellular matrix proteins, fibroblasts, and fibrillins.