Composition of urinary glycosaminoglycans in a patient with pseudoxanthoma elasticum and familial Mediterranean fever

Pseudoxanthoma elasticum (PXE) is a genetic disorder whose gene (ABCC6) encodes a transmembrane transporter called ABCC6/MRP6 [1], and characterized by a connective tissue disorder with accumulation of ion precipitates within the elastic fibers of skin, eyes and the whole cardiovascular system, and by collagen fibril abnormalities and accumulation in the extracellular space of abnormal masses of materials containing proteoglycans and a series of other matrix molecules. Familial Mediterranean fever (FMF) is an autosomal recessive disease characterised by fever and polyserositis [2]. The disease is caused by a defect in the gene encoding pyrin that is effective in the inflammatory response of neutrophils and monocytes. The most important complication of FMF is the development of secondary amyloidosis. Changes on the composition and structure of urinary glycosaminoglycans (GAGs) have been suggested as clinical markers in various diseases, including different types of cancer [3] and PXE [4]. We report a case of a French patient affected by PXE and FMF with amyloidosis in which the composition of urinary GAGs was quantitatively and qualitatively evaluated.