Assignment of two Japanese xeroderma pigmentosum patients to complementation group D and their characteristics.

Japanese xeroderma pigmentosum sib patients XP58TO and XP59TO were assigned to complementation group D on the basis of cell hybridization studies. Ultraviolet and 4-nitroquinoline-1-oxide hypersensitivity and reduced unscheduled DNA synthesis of cells of these XP patients were also characteristic of authentic group-D cells. The patients have not yet developed either apparent neuromental abnormalities or skin cancers.