X-linked erythropoietic protoporphyria

X-linked erythropoietic protoporphyria is a rare condition that affects the way the body makes a molecule called protoporphyrin IX (PPIX). The disease is caused by a change in the ALAS2 gene that results in increased activity of this enzyme. As a result, there is an upregulation in the pathway that produces PPIX. In people with this condition, especially males, the increased levels of PPIX can lead to severe skin sensitivity to sunlight and may also be linked to signs of liver disease. The condition is inherited in an X-linked pattern, which means males with the change often have more marked symptoms, while females can have a wide range of severity due to random X-chromosome inactivation.

People with this condition, particularly males with one affected copy of the gene, often show severe skin reactions to sunlight at an early age. Some affected individuals also exhibit abnormal laboratory markers that suggest liver involvement. The severity of symptoms can vary, with heterozygous females sometimes having milder symptoms or being asymptomatic.

This condition is caused by a gain-of-function variant in the ALAS2 gene located in the terminal regulatory exon. The change in the gene leads to an increase in enzyme activity, which in turn causes a buildup of protoporphyrin IX. The disorder follows an X-linked inheritance pattern, where males who carry the variant usually show symptoms early in life and females can have a wide range of symptom severity due to the process of random X-chromosome inactivation.

Information about treatment is currently limited for this condition.

Information about prognosis is currently limited for this condition.

Information about current research and future directions is currently limited for this condition.