TABLE 3.

Symptomatology and microcephaly mechanistic of NER deficiency.

Human patients
NER factor	Microcephaly	Radiosensitivity	Developmental delay	Immunodeficiency	Predisposition to cancer
XPA	Yes	Yes	Yes	Yes	Yes
XPB	Yes	Yes	No	-	Yes
XPC	Yes	Yes	No	Yes	Yes
XPD	Yes	Yes	Yes	Yes	Yes
XPF	Yes	Yes	Yes	-	-
XPG	Yes	Yes	Yes	-	-
CSA	Yes	Yes	Yes	No	No
CSB	Yes	Yes	Yes	No	No

Mouse models
NER factor	Viability	Radiosensitivity	Affected brain cells	Mechanism
Csa	Viable	Yes	-	-
Csb	Viable	Yes	-	-
Csb/Xpa	Lethal	Yes	Cerebellar external granular layer, Purkinje cells	Decreased neuronal proliferation, increased apoptosis
Csb/Xpc	Lethal	Yes	Cerebellar external granular layer, Purkinje cells	Decreased neuronal proliferation, increased apoptosis