[Monoclonal gammapathy in the adult population of Finistère (France). Results of an inquiry resting on 30,279 persons (author's transl)].

The study of 30,279 adult sera, most issued from Finistère, detected 334 monoclonal gammapathies. The analysis of the results discloses that monoclonal gammapathies appear more frequently in this district (Finistère) than in Paris' one and that their repartition is not homogeneous. Two areas seem to be more particularly affected: one in the north-east, where IgG paraproteins are particularly frequent and the other in southwest, more particularly touched by IgM. The role of a genetic tendency could be backed by a discovery of numerous cases of monoclonal gammapathies occuring in families, and the high rate occuring between "half brother and sisters", but the case study of three couples would be more in favor of an environmental stimulus.