Assignment of 2 patients with xeroderma pigmentosum to complementation group E.
Xeroderma pigmentosum (XP) fibroblast strains derived from XP24KO and XP26KO patients with mild clinical manifestations were similarly twice as sensitive to 254 nm UV killing as normal cells and had a reduced level of 30-55% unscheduled DNA synthesis (UDS) after irradiation with 10 J/m2. Complementation analysis in the hybridized heterodikaryons revealed that XP24KO and XP26KO cells were only unable to complement the reference XP2RO group E cells, despite sufficient complementation to give rise to the normal level of UV-induced UDS with cells of all the other reference XP groups. Nor did XP24KO cells complement XP26KO cells. Therefore, the above 2 unrelated XP patients were assigned to complementation group E. The present group E assignment is the first in Japan, and perhaps the second in the world, the first being the XP2RO/XP3RO second-cousin relationship in The Netherlands (now 4 patients in group E).
D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D004260:DNA Repair; D005816:Genetic Complementation Test; D008040:Genetic Linkage; D006801:Humans; D006822:Hybrid Cells; D009154:Mutation / Q000528:radiation effects; D014983:Xeroderma Pigmentosum / Q000235:genetics*