[Diffuse familial interstitial pulmonary fibrosis. Study of a family].

A study of the genealogy of a 53 year old lady (A.M...) suffering from diffuse interstitial pulmonary fibrosis (FID) has revealed several cases of FID in her forbears and relations. Two brothers of A.M... died of histologically proven FID; FID was also discovered in one of their daughters. A sister died young of some unclassified respiratory problem. Two cousins died likewise at a young age of acute FID proven histologically. The level of spontaneous pneumothorax was particularly elevated in this family which represented a clinical peculiarity when compared to sporadic FID. The most probable mode of transmission of familial FID is autosomal dominant with variable penetrance. The HLA group seen in A.M... showed the A2 and B12 alleles. The B12 allele was also present in the niece of A.M...