This report describes xeroderma pigmentosum, complementation group D (XPD), which is a subtype of xeroderma pigmentosum; XPD exhibits autosomal recessive inheritance. The human gene implicated in this disease is Excision Repair Cross-Complementation Group 2 (ERCC2), which is encodes a DNA helicase that is a component of the TFIIH basal transcription factor. There is a single fly ortholog, Xpd, for which classical loss-of-function alleles, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated. ERCC2 is also implicated in several other human diseases, including a subtype of trichothiodystrophy (TTD; see MIM:126340 and human disease model report FBhh0000709).
The human ERCC2 gene has not been introduced into flies.
Variant(s) implicated in human disease tested (as analogous mutation in fly gene): R112H in the fly Xpd gene (corresponds to R112H in the human ERCC2 gene); R683W in the fly Xpd gene (corresponds to R683W in the human ERCC2 gene); D234N in the fly Xpd gene (corresponds to D234N in the human ERCC2 gene); G47R in the fly Xpd gene (corresponds to G47R in the human ERCC2 gene); G675R in the fly Xpd gene (corresponds to G675R in the human ERCC2 gene); R601L in the fly Xpd gene (corresponds to R601L in the human ERCC2 gene). In addition, a variant analogous to one implicated in TTD1 has been characterized; see FBhh0000709.
Amorphic alleles of the Drosophila Xpd gene are lethal during late embryogenesis; embryonic phenotypes, including radiation sensitivity, have been assayed. Physical and genetic interactions of Dmel\Xpd have been described; see below and in the Xpd gene report.
[updated Jan. 2018 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 D; XPD](https://omim.org/entry/278730)
[ERCC EXCISION REPAIR 2, TFIIH CORE COMPLEX HELICASE SUBUNIT; ERCC2](https://omim.org/entry/126340)
See general description above.
Xeroderma pigmentosum complementation group D (XPD) is caused by homozygous or compound heterozygous mutation in the excision repair gene ERCC2. [from MIM:278730; 2016.03.09]
ERCC2 encodes an ATP-dependent DNA helicase that functions in nucleotide excision repair as a component of the core-TFIIH basal transcription factor. ERCC2 belongs to the RAD3/XPD subfamily of helicases. [from Gene Cards, ERCC2; 2016.03.23]
One to one: 1 human to 1 Drosophila.
High-scoring ortholog of human ERCC2 (1 Drosophila to 1 human). Dmel\Xpd shares 69% identity and 84% similarity with the human gene.