Pseudoxanthoma Elasticum-Like Phenotypes: More Diseases than One Jouni Uitto, Qiujie Jiang  Journal of Investigative Dermatology  Volume 127, Issue 3, Pages 507-510 (March 2007) DOI: 10.1038/sj.jid.5700635 Copyright © 2007 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 1 Representation of pseudoxanthoma elasticum (PXE) as a generalized, multiorgan disease inherited in an autosomal recessive fashion. PXE is caused by mutations in the ABCC6 gene, which encodes multidrug resistance-associated protein 6 (MRP6), primarily expressed in the liver. This protein is postulated to serve as an efflux pump on the basolateral surface of hepatocytes transporting substrate molecules from the intracellular milieu to blood. In the absence of MRP6 transporter activity in the liver (red Xs, middle panels), the blood levels of currently uncharacterized metabolites may change, and this process leads to ectopic mineralization of connective tissue in a number of organs, including the retina of the eye, the blood vessel walls, and the dermis of the skin (middle panels). The mineralization process can be visualized by specific stains, such as alizarin red, as shown in the left panels (open arrows) in the corresponding tissues from an Abcc6–/– mouse, which recapitulates the genetic, histopathologic, and ultrastructural features of human PXE (Klement et al., 2005). Journal of Investigative Dermatology 2007 127, 507-510DOI: (10.1038/sj.jid.5700635) Copyright © 2007 The Society for Investigative Dermatology, Inc Terms and Conditions