Study of the Association between SNP8NRG241930 in the 5’ End of Neuroglin 1 Gene with Schizophrenia in a Group of Iranian Patients

Objective: Neuregulin1 (NRG1) gene is among the most promising candidate genes forschizophrenia. This gene is located on 8p22-p12, a region with a reported linkage to schizophrenia.Several studies have reported an association between schizophrenia and the5′ end polymorphisms in this gene. However, some studies have failed to confirm the roleof NRG1 gene in the pathogenesis of schizophrenia. In the current study, we attempt toexamine the association of SNP8NRG241930 from the NRG1 gene with schizophrenia inan Iranian population. It is noteworthy that there has been no report on the NRG1 associationwith schizophrenia in a population from the Middle East region.Materials and Methods: Genomic DNA samples were obtained via isolation from theperipheral blood cells of 95 unrelated subjects with schizophrenia and 95 matchedhealthy controls from southwest Iran. SNP8NRG241930 was genotyped by PCRRFLPusing ScaI as a restriction endonuclease enzyme. Association of the SNP withschizophrenia was examined using the chi-square test. The frequency difference of allelesand genotypes between the two groups were compared. P≤0.05 was consideredsignificant.Results: Statistical analysis on the studied polymorphism showed that both case and controlgroups were in Hardy-Weinberg equilibrium. The frequency of high risk allele (G allele)was 72.6% in patients, while this number was 56.8% in controls. The genotype frequenciesin the patient group were as follows: GG (54%), GT (38%) and TT (8%) vs. genotypefrequencies in the control group of: GG (26%), GT (63 %) and TT (11%).Conclusion: Considering allele and genotype frequencies, a significant associationwas observed between schizophrenia and SNP8NRG241930. The current study addsweight to the idea that some functional polymorphisms could exist in the 5′ end of theNRG1 gene which increase susceptibility to schizophrenia. This is the first time thatsupportive evidence shows an involvement of the NRG1 locus in schizophrenia in anIranian sample population