title: UV-light induced sister chromatid exchanges in xeroderma pigmentosum lymphocytes.
abstract: Cultured lymphocytes from 9 patients with clinically different types of xeroderma pigmentosum were exposed to ultraviolet light at 24 h. An increased rate of sister chromatid exchanges were observed in 6 patients (128--148% increase in three, 34--51% in three), but not in three patients with deSanctis-Cacchione syndrome (xeroderma pigmentosum with mental defect), compared to simultaneously cultured controls. A positive result could be useful as preliminary cytogenetic diagnostic test. The results are interpreted as an expression of UV-light induced chromosomal instability due to impaired DNA repair.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002842:Chromatids / Q000528:radiation effects*; D003434:Crossing Over, Genetic / Q000528:radiation effects*; D004247:DNA / Q000528:radiation effects; D004260:DNA Repair; D005260:Female; D006801:Humans; D008297:Male; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000235:genetics*
chemical_list: D004247:DNA