Pseudoxanthoma elasticum, recessive form

Pseudoxanthoma Elasticum, Recessive Form (PXE) is a rare genetic disorder characterized by the progressive calcification, fragmentation, and degeneration of elastic fibers in the connective tissue. This condition primarily affects the skin, eyes, and cardiovascular system. The recessive form of PXE is caused by mutations in the ABCC6 gene and is inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to be affected.

Symptoms and Signs

The symptoms of Pseudoxanthoma Elasticum, Recessive Form, can vary widely among individuals but typically include:

• Skin Manifestations: Yellowish papules or plaques that are often found on the neck, underarms, and other flexural areas. These skin changes are due to the accumulation of altered elastic fibers in the dermis.
• Ocular Manifestations: Individuals may experience changes in their vision due to abnormalities in the Bruch's membrane of the retina, leading to angioid streaks, choroidal neovascularization, and, in severe cases, loss of vision.
• Cardiovascular Manifestations: PXE can lead to increased rigidity of blood vessels, contributing to hypertension, coronary artery disease, and other cardiovascular complications.

Genetics

The recessive form of PXE is associated with mutations in the ABCC6 gene, which is located on chromosome 16. This gene encodes a protein that is believed to play a role in the transport of molecules across cell membranes, including those involved in the regulation of elastic fiber formation. The exact mechanism by which mutations in the ABCC6 gene lead to the symptoms of PXE is not fully understood.

Diagnosis

Diagnosis of Pseudoxanthoma Elasticum, Recessive Form, is based on a combination of clinical examination, family history, and genetic testing. Skin biopsy may be used to observe the characteristic changes in elastic fibers. Genetic testing can confirm the presence of mutations in the ABCC6 gene.

Treatment

There is no cure for PXE, and treatment focuses on managing symptoms and preventing complications. This may include:

• Regular monitoring of the cardiovascular system, eyes, and skin.
• Use of anti-vascular endothelial growth factor (anti-VEGF) injections for the treatment of choroidal neovascularization in the eyes.
• Lifestyle modifications and medications to manage cardiovascular risk factors.

Prognosis

The prognosis for individuals with Pseudoxanthoma Elasticum, Recessive Form, varies depending on the severity of symptoms and the development of complications. With appropriate management, many individuals can lead relatively normal lives.