Karotenodermia

Karotenodermia is a rare genetic disorder characterized by the accumulation of carotenoids in the skin, leading to a yellowish or orange discoloration. The condition is caused by mutations in the ABCC6 gene, which encodes a protein involved in the transport of carotenoids out of cells. The exact mechanism by which these mutations result in karotenodermia is not fully understood, but it is believed to involve an impairment in the normal processing and excretion of carotenoids.

Karotenodermia typically presents in infancy or early childhood, with the most common form being the yellow variant. The yellow variant is usually asymptomatic and does not require treatment. However, the orange variant can be associated with symptoms such as photosensitivity, skin fragility, and an increased risk of skin cancer. In some cases, the orange variant may also be associated with other systemic symptoms, such as liver dysfunction and neurological abnormalities.

The diagnosis of karotenodermia is typically made based on the characteristic skin discoloration and a family history of the condition. Genetic testing can confirm the diagnosis and identify the specific mutation in the ABCC6 gene. There is currently no cure for karotenodermia, but management may include photoprotection, topical treatments to reduce skin fragility, and monitoring for any associated systemic symptoms.

Karotenodermia is a rare condition, with an estimated prevalence of less than 1 in 1 million. It is inherited in an autosomal recessive pattern, meaning that both copies of the ABCC6 gene must be mutated for the condition to occur. The condition is more commonly found in populations of European descent.