Why does a person with xeroderma pigmentosum XP exhibit sensitivity to sunlight and have a predisposition to skin cancer?

Why does a person with xeroderma pigmentosum XP exhibit sensitivity to sunlight and have a predisposition to skin cancer?

The major features of xeroderma pigmentosum result from a buildup of unrepaired DNA damage. When UV rays damage genes that control cell growth and division, cells can either die or grow too fast and in an uncontrolled way. Unregulated cell growth can lead to the development of cancerous tumors .

What is the cause of XP sun disease?

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.

Which defect occurs in xeroderma pigmentosum?

The basic defect in xeroderma pigmentosum is in nucleotide excision repair (NER), leading to deficient repair of DNA damaged by UV radiation. This extensively studied process consists of the removal and the replacement of damaged DNA with new DNA.

What type of mutation is xeroderma pigmentosum?

Xeroderma pigmentosum (XP) is a rare autosomal recessive genodermatosis with a markedly elevated risk of developing sunlight-induced cancers of the skin and eyes (Kraemer et al., 2007). XP is caused by mutations in DNA repair genes that protect cells from UV-induced DNA damage.

What is XP disorder?

People who have an extreme sensitivity to sunlight are born with a rare disease known as xeroderma pigmentosum (XP). They must take extreme measures to protect their skin from ultraviolet (UV) light. Anything that emits UV light, including the sun and some lightbulbs, can damage their skin.

What is the treatment for xeroderma pigmentosum?

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).

How do you explain xeroderma pigmentosum?

The word “xeroderma” means extremely dry skin and “pigmentosum” refers to the freckles and dark spots. People who have XP may also develop eye problems. Sunlight can cause cancers to form on their eyes or eyelids. Cataracts and other eye problems may also arise.

What are the signs of XP?

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.

What is a common finding on the eyes of xeroderma pigmentosum patients?

Ocular findings in XP include photophobia, conjunctivitis, ectropion, exposure keratitis leading to corneal opacification or vascularisation, pterygium, and neoplasia.

Why are there neurological problems in XP?

Neurological disease appears to be associated with the complementation group and the failure of fibroblasts to recover RNA synthesis following UV irradiation, but not necessarily to the severity of the dermatological symptoms, the hypersensitivity of fibroblasts to UVB killing or the susceptibility of keratinocytes to …