Types There are seven complementation groups, plus one variant form: Type Diseases Database OMIM Gene Locus Also known as / description Type A, I,<unk> A<unk> A 9q22.3<unk>  group A - the classical form of<unk>  Type B, II,<unk> B<unk> B 2q21<unk>  group B Type C, III,<unk> C<unk> C 3p25<unk>  group C Type D, IV,<unk> D<unk> D ERCC6 19q13.2-q13.3, 10q11<unk>  group D or De Sanctis-Cacchione syndrome (can be considered a subtype of<unk> D) Type E, V,<unk> E DDB2 11p12-p11<unk>  group E Type F, VI,<unk> F ERCC4 16p13.3-p13.13<unk>  group F Type G, VII,<unk> G RAD2 ERCC5 13q33<unk>  group G and COFS syndrome type 3 Type V,<unk> V POLH 6p21.1-p12<unk>  variant - these patients have mutation in a gene that codes for a specialized DNA polymerase called polymerase-η (eta). Polymerase-η can replicate over the damage and is needed when cells enter S-phase in the presence of a DNA-replication.
Xeroderma pigmentosum
Cockayne syndrome
Iododerma
Erythropoietic protoporphyria
Chyloderma
Trichothiodystrophy
Keratoderma
Poikiloderma