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ERCC3 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

ERCC3 gene

The ERCC3 gene provides instructions for making the XPB protein, a critical component of the TFIIH complex involved in DNA repair and gene transcription.

Normal Function

The ERCC3 gene provides instructions for making a protein called XPB. This protein is an essential subunit of the general transcription factor 2 H (TFIIH) complex. The TFIIH complex is involved in gene transcription and repairing damaged DNA.

Gene transcription is the first step in protein production. The XPB protein works together with XPD (produced from the ERCC2 gene) to initiate this process. The TFIIH complex also plays an important role in nucleotide excision repair (NER), a mechanism used to fix DNA damaged by UV rays or toxic chemicals. During this process, the XPB protein acts as a wedge, holding open the two strands of DNA so other proteins can remove and replace the damaged section.

Health Conditions Related to Genetic Changes

Trichothiodystrophy

At least one variant in the ERCC3 gene is a rare cause of trichothiodystrophy, a condition characterized by sparse, brittle hair and extreme sensitivity to UV rays. This variant (Thr119Pro) makes the TFIIH complex unstable, reducing its ability to repair DNA damage. Other features, such as slow growth and intellectual disability, likely result from problems with gene transcription.

Xeroderma pigmentosum

At least one variant in the ERCC3 gene (Phe99Ser) is a rare cause of xeroderma pigmentosum. This variant reduces the TFIIH complex's ability to repair DNA, leading to an accumulation of damage that can cause cells to become cancerous. This condition is associated with extreme sun sensitivity and an increased risk of cancer in sun-exposed areas. Some individuals may also experience mild neurological abnormalities, such as hearing loss and poor coordination.

Other disorders

Several variants in the ERCC3 gene can cause xeroderma pigmentosum/Cockayne syndrome (XP/CS) complex. Individuals with this condition may experience extreme sun sensitivity, an increased risk of skin cancer, short stature, hearing loss, poor coordination, and intellectual disability.

Other Names for This Gene

  • basic transcription factor 2 89 kDa subunit
  • BTF2
  • BTF2 p89
  • DNA excision repair protein ERCC-3
  • DNA repair protein complementing XP-B cells
  • ERCC3_HUMAN
  • excision repair cross-complementation group 3
  • excision repair cross-complementing rodent repair deficiency, complementation group 3
  • excision repair cross-complementing rodent repair deficiency, complementation group 3 (xeroderma pigmentosum group B complementing)
  • GTF2H
  • RAD25
  • TFIIH 89 kDa subunit
  • TFIIH basal transcription factor complex 89 kDa subunit
  • TFIIH basal transcription factor complex helicase XPB subunit
  • TFIIH p89
  • xeroderma pigmentosum group B-complementing protein
  • xeroderma pigmentosum, complementation group B

Frequently Asked Questions

Use broad‑spectrum SPF 50+ sunscreen every 2 hours, wear protective clothing, hats, and UV‑blocking sunglasses, and avoid midday sun. Consider a sun‑exposure diary and schedule regular dermatology check‑ups for early skin cancer detection.
ERCC3 mutations are inherited in an autosomal recessive pattern. If you carry one pathogenic allele, each child has a 50 % chance of inheriting that allele. If the partner also carries a pathogenic variant, there is a 25 % chance the child will inherit two defective copies and develop the disease. Genetic counseling can clarify your specific risk.
Early clues include very fine, brittle hair that breaks easily, a characteristic “tiger‑stripe” pattern under polarized light, and developmental delays or growth failure. If these features are present, especially in combination with photosensitivity, a clinician may order an ERCC3 sequencing test.
There is no cure that reverses the underlying DNA repair defect. Management focuses on supportive care: gentle hair care to reduce breakage, topical moisturizers for dry skin, and regular dermatologic surveillance. In some cases, low‑dose retinoids may help improve skin texture, but they must be used cautiously.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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