[Porphyrin diseases with particular emphasis on hereditary].

During the last 10 years our knowledge concerning the basis defect in porphyrias has increased so that a better genetic family advice. The following basis defects were found: 1. Uroporphyrinogen-III-cosynthetase in porphyria erythropoetica congenita, 2. haem-synthetase in protoporphyria erythropoetica, 3. uroporphyrinogen-1-synthetase in porphyria acuta intermittens, 4. uroporphyrinogen-carboxylase in porphyria cutanea tarda. According to this in porphyria cutanea tarda a genetic defect is supposed, which leads to the disease in connection with the environmental factors. On the basis of the biochemical findings a better understanding of the heredity is possible which is discussed in detail.