The HLA and protease inhibitor (Pi) system in erythropoietic (hepatic) protoporphyria. Family studies

: Relations between porphyrias (porphyria cutanea tarda, variegate porphyria) and HLA- or protease inhibitor (Pi-) system were repeatedly found or supposed. Corresponding investigations do not exist for erythropoietic protoporphyria (EP), for which an autosomal dominant mode of inheritance with highly varying expressiveness (additional genes?) is being discussed. Three families with five EP-patients were examined for possible relations between the manifestations of this disease (skin - and liver changes) and the above-mentioned genetic markers. It was remarkable that three of the patients had the HLA A 3, but nobody of the obvious gene-carriers of this disease without clinical manifestations. On the other hand, two ill couples of siblings were genetically different as to HLA A 3. One couple with liver morphological changes each were different as Pi M-carrier and Pi MS-carrier respectively. Thus, relations between the disease and the genetic markers examined could not be proved.