HLA system in senile dementia of Alzheimer type and multi-infarct dementia in Japan.

To clarify the genetic factors in demented patients in Japan, HLA antigens were examined by the authors. They found a significant association between HLA B16 and senile dementia of Alzheimer type. Also a significant difference was observed in the occurrence of HLA Cw 3 between patients with dementia and controls. In the general population the frequency of B16 is higher in Europe and the USA than it is in Japan. So the authors suppose that the difference in the prevalence of senile dementia of Alzheimer type between Japan and other countries is caused by genetic factors.