Association of the VNTR polymorphism in the MIR137 gene with cognitive functions in schizophrenia patients and healthy individuals

The study aimed to analyze the associations between cognitive domains impaired in schizophrenia and the rs58335419 polymorphism located within the schizophrenia GWAS-significant locus, in the gene MIR137 encoding miR-137. Schizophrenia spectrum patients (n = 787) and healthy volunteers without a family history of psychosis (n = 622) completed tests of semantic verbal fluency (VF), attention/working memory, verbal episodic memory, and executive functions. After correction for multiple testing, VF abnormalities were associated with homozygosity for the common allele (with three repeats) in male patients. Similar trends occurred in the pooled sample for attention/working memory and the general index of cognitive functioning. The four-repeat allele was not associated with variance in cognitive performance. The results obtained indicate an association between homozygosity for the common allele at rs58335419 and lower levels of cognitive functions, which is opposite to the effect of this polymorphism on the risk of developing schizophrenia.