What is the cause of xeroderma pigmentosum?

What is the cause of xeroderma pigmentosum?

Xeroderma pigmentosum is caused by mutations in genes that are involved in repairing damaged DNA. DNA can be damaged by UV rays from the sun and by toxic chemicals such as those found in cigarette smoke. Normal cells are usually able to fix DNA damage before it causes problems.

How is XP diagnosed?

A thorough skin exam by a dermatologist, along with a small skin biopsy for laboratory testing, is the standard method for diagnosing XP. Xeroderma Pigmentosum can usually be conclusively diagnosed by measuring the DNA repair function from the skin cells obtained from the biopsy.

When is XP diagnosed?

How is XP diagnosed? XP is suspected when a person shows signs of extreme sun sensitivity. Signs of sun sensitivity include severe burning and blistering with only a small amount of sun exposure or even exposure to indoor fluorescent lights.

What type of mutation causes XP?

XP is a very rare autosomal recessive disorder that occurs in 1 in 250,000 births in the United States (Lehmann, Mcgibbon, & Stefanini, 2011; Menck & Munford, 2014). It is caused by rare, high-penetrant mutations in nucleotide excision repair (NER) genes.

What chromosome is xeroderma pigmentosum on?

Xeroderma pigmentosum complementation group A (MIM ID #278700) is caused by mutations in the XPA gene (MIMID∗ 611153) and the most frequent mutation is a nonsense mutation (c. 682C>T, p. Arg228X) [26]. This gene is located on chromosome nine (9q34.

How do you test for xeroderma pigmentosum?

The xeroderma pigmentosum complementation groups can be determined using cell-fusion techniques followed by assessment of DNA repair or by gene sequencing. Prenatal diagnosis is possible by amniocentesis or chorionic villi sampling. Unscheduled DNA synthesis is the classic method for diagnosis.

What are symptoms of xeroderma pigmentosum?

Symptoms

  • Sunburn that does not heal after just a little bit of sun exposure.
  • Blistering after just a little bit of sun exposure.
  • Spider-like blood vessels under the skin.
  • Patches of discolored skin that get worse, resembling severe aging.
  • Crusting of the skin.
  • Scaling of the skin.
  • Oozing raw skin surface.

Is xeroderma pigmentosum autosomal dominant or recessive?

XP is an autosomal recessive genetic condition caused by alterations (mutations) in nine different genes. Eight of the genes make up the nucleotide excision repair pathway (NER) that identities and repairs UV induced DNA damage. The ninth gene acts to bypass unrepaired damage.

How is xeroderma pigmentosum treated?

There is no cure for xeroderma pigmentosum, so treatment focuses on any problems that are present and preventing future problems from developing. Any cancers or suspicious lesions should be treated or removed by a skin specialist (dermatologist).