title: Genetic aspects of psoriasis: mode of inheritance and action of PUVA on DNA.
abstract: The results of some family and experimental studies related to psoriasis are summarized. Complex segregation analysis of Lomholt's classical family material of psoriasis from the Faroe Islands gave clear evidence of a major locus (additive gene with a frequency of 0.07) plus a strong polygenic component (genetic heritability 0.87). An analysis of another family material showed complete linkage between the major locus for psoriasis and the HLA region. Treatment of cells with 8-methoxypsoralene plus a small dose of UVA induces monoadducts, some of which appear to remain in the DNA for at least 7 days of post-treatment incubation. These monoadducts can be activated to form DNA cross-links by a second, larger UVA dose. 8-Methoxypsoralene plus UVA-induced DNA cross-links can be modified by a repair process which involves the formation of DNA breaks. This process in not observed in XPA cells.
mesh_terms: D004247:DNA / Q000528:radiation effects; D004260:DNA Repair; D008040:Genetic Linkage; D006680:HLA Antigens / Q000235:genetics; D006801:Humans; D011701:PUVA Therapy; D010778:Photochemotherapy; D011565:Psoriasis / Q000188:drug therapy / Q000235:genetics* / Q000532:radiotherapy; D014467:Ultraviolet Therapy
chemical_list: D006680:HLA Antigens; D004247:DNA