The HL-A system and psoriasis.
A study of 157 psoriatic patients showed that 48.4% were HL-A 17 positive (control 6.0%). The relative risk of psoriasis in HL-A 17 positive individuals (14.7) was significantly higher than that reported from other centes, whilst that for HL-A 13 was lower. HL-A 17 was commoner in femal patients and associated with an earlier age of onset of psoriasis than when HL-A 17 was absent. The earlier age of onset in females is largely due to the higher frequency of HL-A 17. Family studies show that often the ingeritance of HL-A 17 is a necessary condition for psoriasis to appear and this probably applies in some instances to HL-A 13. It is likely that there is interaction between HL-A 17 and HL-A 13 and other genes predisposing to psoriasis. In some families there appears to be no association between psoriasis and the HL-A system. The general significance of these findings is discussed.
D000367:Age Factors; D005787:Gene Frequency; D006680:HLA Antigens / Q000032:analysis; D006649:Histocompatibility Antigens; D006801:Humans; D007592:Joint Diseases / Q000150:complications; D010375:Pedigree; D010641:Phenotype; D011565:Psoriasis / Q000453:epidemiology / Q000235:genetics / Q000276:immunology*; D012737:Sex Factors
D006680:HLA Antigens; D006649:Histocompatibility Antigens