Disease Directory Xeroderma Pigmentosum
Dermatological

Xeroderma Pigmentosum

Also known as: XP, nucleotide excision repair deficiency, DeSanctis-Cacchione syndrome

Prevalence

1 in 250,000 (USA/Europe); 1 in 22,000 (Japan)

Onset

Childhood

Type

Autosomal recessive

Gene

XPA-XPG, POLH

About Xeroderma Pigmentosum

Xeroderma pigmentosum is a rare autosomal recessive disorder of DNA repair caused by defects in nucleotide excision repair (NER) pathway genes (XPA through XPG) or the translesion synthesis polymerase POLH (XP variant). Patients are exquisitely sensitive to ultraviolet radiation and develop severe, early-onset sunburn reactions, progressive photodamage of the skin and eyes, and a dramatically elevated risk of cutaneous malignancies — estimated to be more than 10,000-fold above the general population before age 20. Neurological degeneration occurs in a subset of complementation groups, most prominently XPA and XPD, constituting the DeSanctis-Cacchione syndrome variant.

Common Clinical Features

Severe sunburn after minimal UV exposure, often evident in infancy Progressive freckling, lentigines, and mottled hypo- and hyperpigmentation on sun-exposed skin Early-onset multiple skin cancers including squamous cell carcinoma, basal cell carcinoma, and melanoma Photophobia, conjunctivitis, and corneal opacification from UV-induced ocular damage Pterygium formation and eyelid skin cancers causing visual impairment Progressive sensorineural hearing loss and neurological degeneration in XPA and XPD subtypes Atrophy and telangiectasia of sun-exposed skin giving a prematurely aged appearance

Clinical Trial Eligibility Tips

What to know before applying to Xeroderma Pigmentosum trials.

Genetic complementation group (XPA–XPG or XP-V) is frequently an eligibility criterion — confirm the specific subtype through functional NER assay or sequencing before applying to trials.

Prior or concurrent skin malignancies are common in this population; trials vary widely on whether active or historical cancers are exclusionary — review oncology history documentation carefully.

Many trials restrict enrolment to patients without prior systemic chemotherapy for skin cancers; document all past treatments with dates and agents to expedite eligibility review.

Patient Resources

Patient Organization

XP Society

Visit website ↗

Natural History Registry

XP Registry (NIH/NCI)

Join registry ↗

Orphanet

European reference resource for rare diseases (ORPHA:910)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Xeroderma Pigmentosum trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Xeroderma Pigmentosum. Updated daily.

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