Gene polymorphisms of cognitive function in patients with bipolar disorder: A systematic review and meta-analysis

Abstract

Objectives: Evidence showed that the etiology of cognitive impairment in bipolar disorder (BD) is related to genetic susceptibility. But results from many studies evaluating the association between candidate genes and cognitive function in BD are inconsistent. To define the effect of risk target single-nucleotide polymorphisms (SNPs) on the association of cognition in BD, we did a systematic review and meta-analysis to study the risk genetic variants. Methods: A search for literature was conducted through online databases updated as of October 2018. Recruited studies were compared for cognitive difference in BD patients with certain gene polymorphisms. Results: Meta-analyses were conducted, for two SNPs of target genes including brain-derived neurotrophic factor (rs6265) and calcium channel, voltage-dependent, L type, alpha 1C subunit (rs1006737), in the recruited seven studies. Quantitative analysis showed no significance in the association between the polymorphisms of rs6265 or rs1006737 with global intelligence quotient or rs6265 with Wisconsin Card Sorting test in BD. Conclusion: Our results implied that the cognitive impairment in patients with BD might not be explained by a SNP in current evidence. We suggest that further studies with larger sample size and deeper phenotype are needed to elucidate the relevance of gene variant model contributed to the susceptibility of cognitive dysfunction in patients with BD.