The first limitation of our study is related to the relatively small sample size of both study groups (225 patients with schizophrenia and 225 healthy subjects), which, however, accounting for total population of Armenia (about 2,800,000) and the incidence of schizophrenia (1%) is nearly optimal for this population. In addition, the statistical power of this study, indicating the difference in the C1QB rs291982*G allele frequency between the patients and healthy controls for the OR = 2.5 reached 100%, for OR = 2.0 99.9%, while for OR = 1.2 was 38.8%. Secondly, we did not reveal how the C1QB rs291982 SNP, significantly associated with schizophrenia in our study, alters the C1QB function. Replication of these data in other centres/populations is required to confirm our results, and also, in the future investigations of functional effects of this genetic variant would be desirable.