Association between two single nucleotide polymorphisms at corresponding microRNA and schizophrenia in a Chinese population

Numerous linkage and association studies have been performed to identify genetic predispositions to schizophrenic (SCZ) in different populations, but its genetic basis remains unclear. Some findings may provide a clue in understanding the association between abnormal immunity and SCZ. MicroRNA (miRNA) involves in regulating both schizophrenic and immunity as previous reported. And single nucleotide polymorphisms (SNPs) within miRNAs can change their characteristics, resulting in functional and/or phenotypic changes. So two SNPs (hsa-pre-mir-146a rs2910164 G>C and hsa-mir-499 rs3746444 T>C) at two miRNAs, were genotyped to demonstrate their association with susceptibility to SCZ. Polymorphisms were analyzed among 268 Chinese schizophrenic patients and 232 healthy controls by PCR-RFLP and validated by sequencing. No association was found between the two polymorphisms and SCZ either in cases or in controls. SCZ patients with family history showed significant increase of the G allele frequency of rs2910164 in comparison to those without (P = 0.018). The CC genotype frequency of rs3746444 was also higher in the patients having hallucinations than those without hallucinations (P = 0.012). In addition, patients carrying CC genotype of rs3746444 were more likely to be lack of motivation in comparison to normal controls (P = 0.042). Allele and genotype frequency of rs2910164 showed no significant difference between patients and normal subjects or between patients with and without clinical variables. Although patients carrying CC genotype of rs3746444 were found to be more likely to develop hallucination and individuals carrying C allele to lack motivation, there is lacking association between SCZ and the two SNPs at miRNAs, which may regulate immune response.