[The HLA system and porphyria cutanea tarda].

Familiar occurrence of porphyria cutanea tarda (P. C. T.) has led to search for genetic markers of this disease. One of the three contradictory studies in literature showed significant increased frequencies of HLA-A3 and -B7 in the P. C. T. These results are important for the hypothesis that a disorder of iron metabolism linked to the HLA system (HLA-A3) supports a manifestations of the disease. Our investigations don't support generally this hypothesis. In 90 P. C. T.-patients significantly higher frequencies of any HLA-A, -B and -C-locus were not to be found. But we found a statistic guaranteed higher frequency of HLA-A9 in the subgroup (n = 34) of alcoholic induced P. C. T. An association between HLA-A9 and liver diseases is reported somewhere else. The higher percentage of HLA-A3 incidence in this group was not significant. Significant higher frequency of HLA-A9 possibly refers to liver diseases by P. C. T. HLA-A3--association is imagineable with iron-over loaded disorder in this group.