Is schizophrenia an HLA-associated disease?

Certain specificities of the human leukocyte antigen (HLA) system have been shown to be associated with particular diseases. A review of recent studies in schizophrenia shows inconsistent results for schizophrenia as a whole, although a significant increase in HLA A28 remains on combining the data. There are more consistent findings for disease subtypes. In particular, HLA A9 and HLA CW4 are increased in paranoid schizophrenics, while HLA A1 and the A1-B8 haplotype are increased in nuclear forms. It is postulated that the relationship between the schizophrenias and certain HLA types could be due to an influence of the latter upon neuronal post-synaptic membrane sensitivity to central neurotransmitters such as dopamine.