[Porphyria variegata: a study of a large family (author's transl)].

Porphyria variegata (or South-African porphyria) is not a rare disease in Europe. Its transmission, in a Walloon family, is described. The pedigree extends over 7 generations and comprises 184 individuals. It was possible to carry out biological studies on 100 family members. The results of the analyses are presented and discussed. The levels of fecal porphyrines, the presence of cutaneous lesions and the genealogical relationships permitted the establishment of a coherent picture. Three other families suffering from the same disease are briefly reported. A systematic search for carriers of the gene is indispensable in porphyrias. All identified carriers must be warned of the risks they run and must be supplied with a list of medicaments to be avoided. The prevention of cutaneous lesions by beta-carotene is envisaged.