MAOA-uVNTR variations in schizophrenia: case and control study

Background Schizophrenia, a chronic mental disorder, has been recognized as one of the heritable diseases with an increased level of dopamine neurotransmitter. Monoamine oxidase A (MAOA) plays a vital role in the catabolism of dopamine. It is a mitochondrial enzyme which is encoded by the MAOA gene located on the X chromosome. The aim of this study was to detect potential biomarker in order to diagnose schizophrenia. Hence, the association of uVNTR repetitions of the MAOA gene and Schizophrenia was investigated. Method Blood samples were collected from 102 schizophrenic patients (67 males and 35 females), and 103 volunteers with mental health (65 males and 38 females). Genomic DNA was extracted and the uVNTR polymorphisms were examined using specific primed PCR. Results The analysis indicated that genotype 3/3repetition (rep) showed the highest frequency in females. While genotype 4 and 3.5 reps revealed the highest frequencies among schizophrenic patients and healthy controls in men, respectively. There were no significant statistical differences in the number of uVNTR repeats of the MAOA gene between control and case individuals neither in women (OR = 0.35, 95% CI = 0.60–1.43 P = 0.845) nor in men (OR = 0.36, 95% CI = 0.80–1.64, P = 0.365). Conclusion In the current study, the number of uVNTR sequence repetitions located in the promoter of the MAOA gene was not associated with the risk of schizophrenia in Iranian patients.