β2 microglobulin, HLA-A and Notch4 were all expressed in a pattern where inflammatory illness was associated with increased expression in controls but not in subjects with schizophrenia.
However, no significant differences of these allelic frequencies were found between the patients and the control subjects, suggesting that the HLA-A gene was unlikely a major risk factor of schizophrenia in this sample.
While searching for the "true" disease gene near the HLA-A gene, we discovered that homozygosity of the HLA-J M80469 pseudogene allele, in combination with HLA-A10 or HLA-A9, was associated with a high risk of schizophrenia (HLA-A10 relative risk = 29.33, p = 0.00019, patients N = 77, controls N = 214).