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Xeroderma pigmentosum, variant type(XPV)

MedGen UID:
376352
Concept ID:
C1848410
Disease or Syndrome
Synonyms: Photosensitivity with defective DNA synthesis; POLH-Related Xeroderma Pigmentosum; Xeroderma pigmentosum with normal DNA repair rates; XPV
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
141025
Concept ID:
C0441748
Intellectual Product
Sources: HPO, OMIM, Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in homozygotes. In the context of medical genetics, autosomal recessive disorders manifest in homozygotes (with two copies of the mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele).
Autosomal recessive inheritance (HPO, OMIM, Orphanet)
 
Gene (location): POLH (6p21.1)
OMIM®: 278750
Orphanet: ORPHA90342

Disease characteristics

Excerpted from the GeneReview: Xeroderma Pigmentosum
Xeroderma pigmentosum (XP) is characterized by: Sun sensitivity (severe sunburn with blistering, persistent erythema on minimal sun exposure in ~60% of affected individuals), with marked freckle-like pigmentation of the face before age two years in most affected individuals; Sunlight-induced ocular involvement (photophobia, keratitis, atrophy of the skin of the lids); Greatly increased risk of sunlight-induced cutaneous neoplasms (basal cell carcinoma, squamous cell carcinoma, melanoma). Approximately 25% of affected individuals have neurologic manifestations (acquired microcephaly, diminished or absent deep tendon stretch reflexes, progressive sensorineural hearing loss, and progressive cognitive impairment). The most common causes of death are skin cancer, neurologic degeneration, and internal cancer. The median age at death in persons with XP with neurodegeneration (29 years) was found to be younger than that in persons with XP without neurodegeneration (37 years). [from GeneReviews]
Authors:
Kenneth H Kraemer  |  John J DiGiovanna   view full author information

Additional descriptions

From OMIM
Xeroderma pigmentosum is an autosomal recessive disorder characterized by increased sensitivity to sunlight and defects in DNA repair. For a general overview of the disorder, see XPA (278700). Some patients with xeroderma pigmentosum have been found to have normal DNA excision repair, but defective postreplication repair (Lehman et al., 1975). This XP 'variant' class is characterized by a defect in conversion of newly synthesized DNA from low to high molecular weight after UV irradiation (Masutani et al., 1999). So-called 'pigmentary xerodermoid' is apparently identical to the XP variant, which is characterized by loss of a gene product that permits normal cells to replicate DNA without interruption at UV-damaged sites (Cleaver et al., 1980).  http://www.omim.org/entry/278750
From GHR
Xeroderma pigmentosum, which is commonly known as XP, is an inherited condition characterized by an extreme sensitivity to ultraviolet (UV) rays from sunlight. This condition mostly affects the eyes and areas of skin exposed to the sun. Some affected individuals also have problems involving the nervous system.The signs of xeroderma pigmentosum usually appear in infancy or early childhood. Many affected children develop a severe sunburn after spending just a few minutes in the sun. The sunburn causes redness and blistering that can last for weeks. Other affected children do not get sunburned with minimal sun exposure, but instead tan normally. By age 2, almost all children with xeroderma pigmentosum develop freckling of the skin in sun-exposed areas (such as the face, arms, and lips); this type of freckling rarely occurs in young children without the disorder. In affected individuals, exposure to sunlight often causes dry skin (xeroderma) and changes in skin coloring (pigmentation). This combination of features gives the condition its name, xeroderma pigmentosum.People with xeroderma pigmentosum have a greatly increased risk of developing skin cancer. Without sun protection, about half of children with this condition develop their first skin cancer by age 10. Most people with xeroderma pigmentosum develop multiple skin cancers during their lifetime. These cancers occur most often on the face, lips, and eyelids. Cancer can also develop on the scalp, in the eyes, and on the tip of the tongue. Studies suggest that people with xeroderma pigmentosum may also have an increased risk of other types of cancer, including brain tumors. Additionally, affected individuals who smoke cigarettes have a significantly increased risk of lung cancer.The eyes of people with xeroderma pigmentosum may be painfully sensitive to UV rays from the sun. If the eyes are not protected from the sun, they may become bloodshot and irritated, and the clear front covering of the eyes (the cornea) may become cloudy. In some people, the eyelashes fall out and the eyelids may be thin and turn abnormally inward or outward. In addition to an increased risk of eye cancer, xeroderma pigmentosum is associated with noncancerous growths on the eye. Many of these eye abnormalities can impair vision.About 30 percent of people with xeroderma pigmentosum develop progressive neurological abnormalities in addition to problems involving the skin and eyes. These abnormalities can include hearing loss, poor coordination, difficulty walking, movement problems, loss of intellectual function, difficulty swallowing and talking, and seizures. When these neurological problems occur, they tend to worsen with time.Researchers have identified at least eight inherited forms of xeroderma pigmentosum: complementation group A (XP-A) through complementation group G (XP-G) plus a variant type (XP-V). The types are distinguished by their genetic cause. All of the types increase skin cancer risk, although some are more likely than others to be associated with neurological abnormalities.  https://ghr.nlm.nih.gov/condition/xeroderma-pigmentosum

Clinical features

Conjunctivitis
MedGen UID:
1093
Concept ID:
C0009763
Disease or Syndrome
Inflammation of the conjunctiva.
Keratitis
MedGen UID:
44013
Concept ID:
C0022568
Disease or Syndrome
Inflammation of the cornea.
Photophobia
MedGen UID:
43220
Concept ID:
C0085636
Sign or Symptom
Abnormal sensitivity to light. This may occur as a manifestation of EYE DISEASES; MIGRAINE; SUBARACHNOID HEMORRHAGE; MENINGITIS; and other disorders. Photophobia may also occur in association with DEPRESSION and other MENTAL DISORDERS.
Carcinoma, Basal Cell
MedGen UID:
2870
Concept ID:
C0007117
Neoplastic Process
A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1471)
Squamous cell carcinoma
MedGen UID:
2874
Concept ID:
C0007137
Neoplastic Process
The presence of squamous cell carcinoma of the skin.
Malignant melanoma
MedGen UID:
9944
Concept ID:
C0025202
Neoplastic Process
Melanoma is the most serious type of skin cancer. Often the first sign of melanoma is a change in the size, shape, color, or feel of a mole. Most melanomas have a black or black-blue area. Melanoma may also appear as a new mole. It may be black, abnormal, or ugly looking.. Thinking of ABCDE can help you remember what to watch for:. - Asymmetry - the shape of one half does not match the other. - Border - the edges are ragged, blurred or irregular. - Color - the color is uneven and may include shades of black, brown and tan. - Diameter - there is a change in size, usually an increase. -Evolving - the mole has changed over the past few weeks or months. Surgery is the first treatment of all stages of melanoma. Other treatments include chemotherapy and radiation, biologic, and targeted therapies. Biologic therapy boosts your body's own ability to fight cancer. Targeted therapy uses substances that attack cancer cells without harming normal cells. NIH: National Cancer Institute.
Conjunctivitis
MedGen UID:
1093
Concept ID:
C0009763
Disease or Syndrome
Inflammation of the conjunctiva.
Spider veins
MedGen UID:
215068
Concept ID:
C1138421
Finding
Telangiectasias refer to small dilated blood vessels located near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. Telangiectasia are located especially on the tongue, lips, palate, fingers, face, conjunctiva, trunk, nail beds, and fingertips.
Growth delay
MedGen UID:
765377
Concept ID:
C3552463
Sign or Symptom
A deficiency or slowing down of growth pre- and postnatally.
Photophobia
MedGen UID:
43220
Concept ID:
C0085636
Sign or Symptom
Abnormal sensitivity to light. This may occur as a manifestation of EYE DISEASES; MIGRAINE; SUBARACHNOID HEMORRHAGE; MENINGITIS; and other disorders. Photophobia may also occur in association with DEPRESSION and other MENTAL DISORDERS.
Microcephaly
MedGen UID:
473122
Concept ID:
C0424688
Finding
Occipito-frontal (head) circumference (OFC) less than -3 standard deviations compared to appropriate, age matched, normal standards (Ross JJ, Frias JL 1977, PMID:9683597). Alternatively, decreased size of the cranium.
Conjunctivitis
MedGen UID:
1093
Concept ID:
C0009763
Disease or Syndrome
Inflammation of the conjunctiva.
Keratitis
MedGen UID:
44013
Concept ID:
C0022568
Disease or Syndrome
Inflammation of the cornea.
Microcephaly
MedGen UID:
473122
Concept ID:
C0424688
Finding
Occipito-frontal (head) circumference (OFC) less than -3 standard deviations compared to appropriate, age matched, normal standards (Ross JJ, Frias JL 1977, PMID:9683597). Alternatively, decreased size of the cranium.
Conjunctivitis
MedGen UID:
1093
Concept ID:
C0009763
Disease or Syndrome
Inflammation of the conjunctiva.
Ectropion
MedGen UID:
4448
Concept ID:
C0013592
Disease or Syndrome
The structure representing the everted margin of a part
Entropion
MedGen UID:
41813
Concept ID:
C0014390
Disease or Syndrome
An inward turning (inversion) of the eyelid margin.
Microcephaly
MedGen UID:
473122
Concept ID:
C0424688
Finding
Occipito-frontal (head) circumference (OFC) less than -3 standard deviations compared to appropriate, age matched, normal standards (Ross JJ, Frias JL 1977, PMID:9683597). Alternatively, decreased size of the cranium.
Carcinoma, Basal Cell
MedGen UID:
2870
Concept ID:
C0007117
Neoplastic Process
A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1471)
Squamous cell carcinoma
MedGen UID:
2874
Concept ID:
C0007137
Neoplastic Process
The presence of squamous cell carcinoma of the skin.
Malignant melanoma
MedGen UID:
9944
Concept ID:
C0025202
Neoplastic Process
Melanoma is the most serious type of skin cancer. Often the first sign of melanoma is a change in the size, shape, color, or feel of a mole. Most melanomas have a black or black-blue area. Melanoma may also appear as a new mole. It may be black, abnormal, or ugly looking.. Thinking of ABCDE can help you remember what to watch for:. - Asymmetry - the shape of one half does not match the other. - Border - the edges are ragged, blurred or irregular. - Color - the color is uneven and may include shades of black, brown and tan. - Diameter - there is a change in size, usually an increase. -Evolving - the mole has changed over the past few weeks or months. Surgery is the first treatment of all stages of melanoma. Other treatments include chemotherapy and radiation, biologic, and targeted therapies. Biologic therapy boosts your body's own ability to fight cancer. Targeted therapy uses substances that attack cancer cells without harming normal cells. NIH: National Cancer Institute.
Dermal atrophy
MedGen UID:
101793
Concept ID:
C0151514
Disease or Syndrome
Partial or complete wasting (atrophy) of the skin.
Cutaneous photosensitivity
MedGen UID:
87601
Concept ID:
C0349506
Pathologic Function
increased sensitivity of the skin to light and other sources of UV
Poikiloderma
MedGen UID:
97905
Concept ID:
C0392777
Disease or Syndrome
Poikiloderma refers to a patch of skin with (1) reticulated hypopigmentation and hyperpigmentation, (2) wrinkling secondary to epidermal atrophy, and (3) telangiectasias.
Spider veins
MedGen UID:
215068
Concept ID:
C1138421
Finding
Telangiectasias refer to small dilated blood vessels located near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. Telangiectasia are located especially on the tongue, lips, palate, fingers, face, conjunctiva, trunk, nail beds, and fingertips.

Term Hierarchy

Recent clinical studies

Therapy

Tayeb T, Laure B, Sury F, Lorette G, Goga D
J Craniomaxillofac Surg 2011 Oct;39(7):496-8. Epub 2010 Aug 21 doi: 10.1016/j.jcms.2010.03.026. PMID: 20728371

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