HLA-SD antigens and schizophrenia: statistical and genetical considerations.

The HLA-SD phenotype distributions of hebephrenic and paranoid schizophrenics, and of the two groups combined, in an Italian population and in a combined group from the Swedish population have been analyzed statistically. There is a significantly decreased frequency of HLA-A10 in all of these. Theae are some preliminary indications of an increased frequency (a positive association) for some of the other antigens of the HLA-SD series, but there is insufficient data at present for evaluating the significance of these findings. Differences between hebephrenic and paranoid schizophrenics have been detected.