Pseudoxanthoma elasticum (PXE)

The disease is clinically heterogeneous, in some patients it can be limited to one organ, in others it can affect all three systems. Skin lesions appear mainly in the flexion of the neck and elbows, in the popliteal fossa and in the navel, and are accompanied by skin laxity. At the ocular level, it can manifest itself as anomalies of the retinal pigment epithelium, drusen, angioid striae and the formation of new vessels, bleeding from which causes retinal hemorrhages and, in many patients, blindness. Involvement of the macula can lead to patients being considered blind. Cardiovascular manifestations lead to intermittent claudication of the lower and / or upper extremities due to early atherosclerosis of the middle arteries with calcification of the vessel walls. Gastrointestinal bleeding occurs in 5% of cases, especially during adolescence. The disease is transmitted in an autosomal recessive manner. Sporadic cases of affection of family members in two successive generations are more likely associated with pseudo-dominance than with autosomal dominant inheritance. PXE arises from homozygous or complex heterozygous mutations in the ABCC6 gene (16p13.1), which encodes a transmembrane protein belonging to the ABC transporter superfamily (ATP-binding cassette transporters).