Editing Xeroderma pigmentosum (section)

{{infobox medical condition (new)
| name          = Xeroderma pigmentosum
| synonyms      = [[DeSanctis-Cacchione syndrome]]<ref name=GHR2018/><ref name=Derm2017/>

XP1 / XP2 / XP3 / XP4 / XP5 / XP6 / XP7<ref name="myriad1">{{Cite web |title=Not found |url=https://myriad.com/womens-health/2014/05/hello-world/ |url-status=dead |archive-url=https://web.archive.org/web/20221026171206/https://myriad.com/womens-health/2014/05/hello-world/ |archive-date=2022-10-26 |access-date=2023-03-06}}</ref>

Xeroderma pigmentosum I/II/III/IV/V/VI/VII<ref name="myriad1" />

Xeroderma pigmentosum complementation group A/B/C/D/E/F/G<ref name="myriad1" />

xeroderma pigmentosum group A/B/C/D/E/F/G<ref name="myriad1" />
| image         = Xeroderma pigmentosum 02.jpg
| field         = [[Medical genetics]]
| caption       = An eight-year-old girl from [[Guatemala]] with xeroderma pigmentosum<ref name="Halpern_2008" />
| symptoms      = Severe [[sunburn]] after only a few minutes in the sun, [[freckling]] in sun-exposed areas, dry skin, changes in skin pigmentation<ref name=GHR2018/>
| complications = [[Skin cancer]], [[brain cancer]], [[cataracts]]<ref name=GHR2018/>
| onset         = Becomes visible ~6 months of age<ref name="Derm2017">{{Cite web |title=Xeroderma pigmentosum |url=https://dermnetnz.org/topics/xeroderma-pigmentosum/ |access-date=25 February 2020 |website=dermnetnz.org}}</ref>
| duration      = Lifelong
| types         =
| causes        = [[Genetic disorder]] ([[autosomal recessive]])<ref name=GHR2018/>
| diagnosis     = Based on symptoms and confirmed by [[genetic testing]]<ref name=NORD2017/>
| differential  = [[Trichothiodystrophy]], [[Cockayne syndrome]], [[cerebrooculofacioskeletal syndrome]], [[erythropoietic protoporphyria]]<ref name=GARD2018/>
| prevention    = No cure available
| treatment     = Completely avoiding sun or UV rays, [[retinoid cream]]s, [[vitamin D]]<ref name=NORD2017/><ref name=GARD2018/>
| prognosis     = [[Life expectancy]] is shortened by about 30 years.<ref name=Ah2008/>
| frequency     = • 1 in 100,000 (worldwide)<ref name="myriad1" />

• 1 in 370 (India) {{cn|date=November 2023}}

• 1 in 22,000 (Japan)<ref name="myriad1" />

• 1 in 250,000 (US)<ref name=Leh2011/>

• 1 in 430,000 (Europe)

• 1 in 1,000,000 (UK)<ref name="myriad1" />
| deaths        =
| alt           =
}}
<!-- Definition and symptoms -->
'''Xeroderma pigmentosum''' ('''XP''') is a [[genetic disorder]] in which there is a decreased ability to repair [[DNA damage]] such as that caused by [[ultraviolet]] (UV) light.<ref name="GHR2018">{{Cite web |date=26 June 2018 |title=Xeroderma pigmentosum |url=https://ghr.nlm.nih.gov/condition/xeroderma-pigmentosum |access-date=28 June 2018 |website=Genetics Home Reference |publisher=U.S. Library of Medicine}}</ref> Symptoms may include a severe [[sunburn]] after only a few minutes in the sun, [[freckling]] in sun-exposed areas, [[dry skin]] and changes in skin pigmentation.<ref name=GHR2018/> Nervous system problems, such as [[hearing loss]], poor coordination, loss of intellectual function and [[seizures]], may also occur.<ref name=GHR2018/> Complications include a high risk of [[skin cancer]], with about half having skin cancer by age 10 without preventative efforts, and [[cataract]]s.<ref name=GHR2018/> There may be a higher risk of other cancers such as [[brain cancer]]s.<ref name=GHR2018/>

<!-- Cause and mechanism -->
XP is [[autosomal recessive]], with [[mutations]] in at least nine specific genes able to result in the condition.<ref name=GHR2018/><ref name="GARD2018">{{Cite web |date=2018 |title=Xeroderma pigmentosum |url=https://rarediseases.info.nih.gov/diseases/7910/xeroderma-pigmentosum |access-date=28 June 2018 |website=Genetic and Rare Diseases Information Center (GARD) |publisher=U.S. Department of Health and Human Services}}</ref> Normally, the damage to [[DNA]] which occurs in [[Epidermis (skin)|skin cells]] from exposure to UV light is repaired by [[nucleotide excision repair]].<ref name=GHR2018/> In people with xeroderma pigmentosum, this damage is not repaired.<ref name=GHR2018/> As more abnormalities form in DNA, cells malfunction and eventually become cancerous or die.<ref name=GHR2018/> Diagnosis is typically suspected based on symptoms and confirmed by [[genetic testing]].<ref name=NORD2017/>

<!-- Treatment and prognosis -->
There is no cure for XP.<ref name=GARD2018/> Treatment involves completely avoiding the [[sun]].<ref name=GARD2018/> This includes protective clothing, [[sunscreen]] and dark sunglasses when out in the sun.<ref name=GARD2018/> [[Retinoid cream]]s may help decrease the risk of skin cancer.<ref name=GARD2018/> [[Vitamin D]] supplementation is generally required.<ref name=NORD2017/> If skin cancer occurs, it is treated in the usual way.<ref name=GARD2018/> The [[life expectancy]] of those with the condition is about 30 years less than normal.<ref name="Ah2008">{{Cite book |last=Ahmad |first=Shamim |url=https://books.google.com/books?id=_MPMriGtLbIC&pg=PA17 |title=Molecular Mechanisms of Xeroderma Pigmentosum |last2=Hanaoka |first2=Fumio |date=2008 |publisher=Springer Science & Business Media |isbn=9780387095998 |page=17 |language=en |name-list-style=vanc}}</ref>

<!-- Epidemiology, history and culture -->
The disease affects about 1 in 100,000 worldwide.<ref name="myriad1" /> By region, it affects about 1 in 370 in India, 1 in 20,000 in Japan, 1 in 250,000 people in the United States and 1 in 430,000 in Europe.<ref name="Leh2011">{{Cite journal |vauthors=Lehmann AR, McGibbon D, Stefanini M |date=November 2011 |title=Xeroderma pigmentosum |journal=Orphanet Journal of Rare Diseases |volume=6 |pages=70 |doi=10.1186/1750-1172-6-70 |pmc=3221642 |pmid=22044607 |doi-access=free}}</ref> It occurs equally commonly in males and females.<ref name=Gri2016/> Xeroderma pigmentosum was first described in the 1870s by [[Moritz Kaposi]].<ref name="NORD2017">{{Cite web |date=2017 |title=Xeroderma Pigmentosum |url=https://rarediseases.org/rare-diseases/xeroderma-pigmentosum/ |access-date=28 June 2018 |website=NORD (National Organization for Rare Disorders)}}</ref><ref name="Gri2016">{{Cite book |last=Griffiths |first=Christopher |url=https://books.google.com/books?id=85AvCgAAQBAJ&pg=RA9-PA41 |title=Rook's Textbook of Dermatology, 4 Volume Set |last2=Barker |first2=Jonathan |last3=Bleiker |first3=Tanya |last4=Chalmers |first4=Robert |last5=Creamer |first5=Daniel |date=2016 |publisher=John Wiley & Sons |isbn=9781118441190 |language=en |name-list-style=vanc}}</ref> In 1882, Kaposi coined the term ''xeroderma pigmentosum'' for the condition, referring to its characteristic dry, pigmented skin.<ref name=Gri2016/> Individuals with the disease have been referred to as "children of the night" or "moon children".<ref>{{Cite book |url=https://books.google.com/books?id=4d7wHD428MwC&pg=PT313 |title=Medical Biochemistry at a Glance |vauthors=Salway JG |date=2011 |publisher=John Wiley & Sons |isbn=9781118292402 |page=313 |language=en}}</ref>