Association of the NOTCH4 gene polymorphism with schizophrenia in the Indian population

Schizophrenia is a chronic serious neuropsychiatric disorder with a prevalence of 1% worldwide. Neurogenic locus NOTCH homolog protein 4 known as the NOTCH4 gene is located on chromosome 6p. NOTCH4 protein is a transmembrane protein that plays a major role in cell signaling pathways and cell differentiation. NOTCH4 SNP rs367398 is located in the gene's largest intron, intron 18, which is an area of known importance in transcriptional regulation and may be related to schizophrenia. Although many studies have shown the association of NOTCH4 polymorphism with schizophrenia, the exact molecular mechanism behind this still unknown. This study was aimed to determine the frequency of NOTCH4 rs367398 & rs387071 polymorphism and its association with schizophrenia. In total, 150 schizophrenia patients and 100 healthy controls were recruited from psychiatry department after obtaining written informed consent. NOTCH4 polymorphism was genotyped using PCR-RFLP. Positive and Negative Syndrome Scale (PANSS) and Global assessment of functioning (GAF) were used to assess the severity of schizophrenia. Both the NOTCH4 rs367398 & rs387071 genotypes were significantly associated with schizophrenia. On gender based analysis, the rs387071 was significantly associated with schizophrenia in males and whereas the rs367398 is associated with females of the study group. Further, the haplotype analysis has also supported the association of NOTCH4 locus with schizophrenia (Global haplotype association p = 0.021). The findings of the study suggest that the NOTCH4 polymorphism is significantly associated with schizophrenia in Indian population. These SNPs might also have an important role in the symptomatology of the disease.