title: Xeroderma pigmentosum complementation group G--report of two cases.
abstract: Genetic complementation studies allowed assignment of a brother (XP124LO) and sister (XP 125LO), aged 14 and 12 years respectively, to the rare complementation group of classical xeroderma pigmentosum (XP), XP-G. Both patients manifested only mild cutaneous changes, with no UV-induced skin tumours, although abnormal sensitivity to UVB wavelengths was demonstrated by irradiation monochromator skin testing. Physical and neurological development was normal. Measurement of UV-induced unscheduled DNA synthesis in cultured fibroblasts showed reduction of repair synthesis to 14% and 16% of normal in XP124LO and XP125LO, respectively. This contrasts with a reduction to 5% of normal in previously described group G patients, XP2BI and XP3BR, who had correspondingly severe cutaneous and neurological manifestations.
mesh_terms: D000293:Adolescent; D002648:Child; D004260:DNA Repair / Q000528:radiation effects; D005260:Female; D005816:Genetic Complementation Test; D006801:Humans; D008297:Male; D012867:Skin / Q000528:radiation effects; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000235:genetics*