UVSSA and USP7: new players regulating transcription-coupled nucleotide excision repair in human cells

Table 1 Clinical, genetic and biochemical comparisons of XP, CS and UV^SS

	XP	CS	UV^SS
Sun-sensitivity	Yes	Yes	Yes
Skin cancers	Yes	No	No
Progressive neurological degeneration	Yes/no^a	Yes	No
Developmental abnormalities	No	Yes	No
Ageing	Yes/no^a	Yes	No
UV-DNA repair deficiency	Yes	Yes	Yes
ROS-DNA repair deficiency	Yes/no^a	Yes	No
Complementation groups	7	2	3
Involved genes	XPA to XPG^b	CSA and CSB	CSA, CSB and UVSSA

^aSome XP patients exhibit XP and CS (mutated on XPA, XPB, XPD and XPG). ^bSeven genes are involved in XP. CS, Cockayne syndrome; ROS, reactive oxygen species; UV, ultraviolet; UV^SS, UV-sensitivity syndrome; XP, xeroderma pigmentosum.