ASSOCIATION OF microRNA137 GENE POLYMORPHISMS WITH AGE AT ONSET AND POSITIVE SYMPTOMS OF SCHIZOPHRENIA IN A HAN CHINESE POPULATION

Objectives: MicroRNA137 (miRNA137) regulates several gene expressions involved in brain development, and a recent large genome wide association study (GWAS) revealed a possible association between miRNA137 and schizophrenia. Methods: The allelic variants of rs66642155, a variable number tandem repeat polymorphism, and the single nucleotide polymorphism rs1625579 A/C in the miRNA137 host gene fragment were compared between 300 schizophrenic patients and 300 healthy controls from the Han Chinese population. The association of these polymorphisms with clinical characteristics of schizophrenia was also tested. Results: Genotype and allele frequencies of these polymorphisms were not significantly different between patient and control populations. In patients, however, age at onset was much later in wild type rs66642155 carriers than in mutation carriers. Total positive score on the Positive and Negative Symptom Scale (PANSS), total five-factor model positive score, and the delusions symptom score were all significantly higher in wild type rs66642155 carriers with schizophrenia, while the disturbance of volition symptom score was significantly higher in the mutation carriers with schizophrenia. Conclusions: MiRNA137 may not be a significant susceptibility gene for schizophrenia, but in patients, rs66642155 allelic variant of miRNA137 appears to influence age at onset and the severity of positive symptoms.