The association between the gene of complement C4A, C4B deficiency and schizophrenia was studied.192 Patients with schizophrenia and 142 healthy controls were tested with the amplification restriction fragment length polymorphism (Amp-RFLP) technique.The frequency of C4AQ0/C4AQ0 homozygote was higher in the patient group than in the control group (X2=8.54, P<0.01).The relative risk (RR) of C4AQ0/C4AQ0 homozygote for schizophrenia was 6.8.There was no increased frequency of C4B deficiency in patients with schizophrenia (X2 =0.11, P>0.05, RR =0.73).These results indicate that there is a pos. association between complement C4A deficiency and schizophrenia.But there is no widespread association between a deficiency in complement component C4B and schizophrenia.
