Association of the manganese superoxide dismutase gene Ala-9Val polymorphism with clinical phenotypes and tardive dyskinesia in schizophrenic patients

Prog Neuropsychopharmacol Biol Psychiatry 34(4):5 (2010) PMID 20346996

Objective: Several recent studies that have investigated the genetic association between the manganese superoxide dismutase (MnSOD) gene Ala-9Val single-nucleotide polymorphism (SNP) and tardive dyskinesia (TD) have produced conflicting results. This study was to investigate whether this SNP was associated with clinical phenotypes and antipsychotic-induced tardive dyskinesia (TD) in schizophrenia in a genetically homogeneous Han Chinese inpatient population. Methods: Genotyping was performed for the MnSOD gene Ala-9Val SNP in Chinese schizophrenia patients with (n=176) and without TD (n=346). The severity of TD was assessed using the abnormal involuntary movement scale (AIMS), and psychopathology using the Positive and Negative Syndrome Scale (PANSS). Results: The frequencies of genotypes and alleles did not differ significantly between schizophrenic patients with and without TD (both p>0.05). Also, there was no significant difference in the AIMS total score between the Val/Val and Ala allele carrier groups (p>0.05). However, the PANSS negative symptom subscore was significantly higher in patients with Val/Val genotype (21.8+/-7.3) than those with Ala alleles (20.1+/-7.7) (t=2.32, p=0.03). Conclusion: While the MnSOD gene Ala-9Val polymorphism did not play a major role in the susceptibility to TD in schizophrenic patients, it might be associated with negative symptoms of schizophrenia.