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 A 10 in all of these. There 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.