“…The combination of exposure to sunlight and liver damage may account for the high frequency of the disease found in South Africa by Barnes. Conigenital Nature of the Disease.-Porphyric bullous dermatosis is a familial disease. Urbach (1937, Case 1) notes the disease in father and son; Gross (1910) and Hudelo and Montlaur (1919) describe cases in brothers and sisters, while Anderson (1898), Templeton and Lunsford (1932), and Brunsting andMason (1946, 1949) record cases in which the patient's mother or sister was symptom-free though excreting porphyrin. Borzow (1933) and Calvy et al (1951) describe families with symptoms in sibs of four or five generations.…”