[Heredity and childhood psychoses : histocompatibility antigens (HLA A and B) and early onset childhood psychoses (author's transl)].

: We first consider current arguments in favor of a genetic etiology of childhood psychoses. These psychoses have to be separated in early psychoses (before age 5) and late onset ones (between 5 years and adolescence). These late onset psychoses appear to be genetically determined and related to schizophrenia, while early psychoses may be in part genetically related and subject to environmental factors. We also report a study on HLA in early onset psychoses in the North of France, which could not show any association between HLA system and the psychoses.