This report describes xeroderma pigmentosum, complementation group B (XPB), which is a subtype of xeroderma pigmentosum; XPB exhibits autosomal recessive inheritance. The human gene implicated in this disease is Excision Repair Cross-Complementation Group 3 (ERCC3), which is encodes a DNA helicase that is a component of the TFIIH basal transcription factor. There is a single fly ortholog, hay, for which classical loss-of-function alleles, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated. ERCC3 is also implicated in the human disease Trichothiodystrophy 2 (MIM:616390).
The human ERCC3 has not been introduced into flies.
Amorphic alleles of the Drosophila hay gene are lethal; temperature-sensitive, hypomorphic, and RNAi alleles have allowed characterization of later stages. UV-sensitivity at the larval stage (assayed as survival to adulthood) is observed. Physical and genetic interactions of Dmel\hay have been described; see below and in the hay gene report.
[updated Jul. 2017 by FlyBase; FBrf0222196]
Xeroderma pigmentosum is characterized by increased sensitivity to sunlight with the development of carcinomas at an early age. Some patients develop neurologic symptoms or a more severe clinical phenotype known as de Sanctis-Cacchione syndrome (MIM:278800) (Satokata et al., 1992; pubmed:1372102). [from MIM:278700; 2016.03.09]
Xeroderma pigmentosum (XP) is an inherited condition characterized by an extreme sensitivity to ultraviolet (UV) rays from sunlight, affecting repeatedly exposed skin and the eyes, and by a greatly increased risk of developing skin cancer. About 30 percent of people with xeroderma pigmentosum also develop progressive neurological abnormalities. [from Genetics Home Reference, Xeroderma pigmentosum; 2016.03.23]
[XERODERMA PIGMENTOSUM, COMPLEMENTATION GROUP B; XPB](https://omim.org/entry/610651)
[ERCC EXCISION REPAIR 3, TFIIH CORE COMPLEX HELICASE SUBUNIT; ERCC3](https://omim.org/entry/133510)
See general description above.
Xeroderma pigmentosum complementation group B (XPB) is caused by homozygous or compound heterozygous mutation in the excision repair gene ERCC3. [from MIM:610651; 2016.03.09]
ERCC3 encodes an ATP-dependent DNA helicase that functions in nucleotide excision repair as a component of the core-TFIIH basal transcription factor. ERCC3 plays a significant role in normal basal transcription, transcription coupled repair (TCR), and nucleotide excision repair (NER). [from Gene Cards, ERCC3; 2016.03.23]
One to one: 1 human to 1 Drosophila.
High-scoring ortholog of human ERCC3 (1 Drosophila to 1 human). Dmel\hay shares 69% identity and 81% similarity with the human gene.
