Genetic association of dopamine beta-hydroxylase (DBH) rs72393728 and D-amino acid oxidase activator (DAOA) rs3918342 polymorphisms with bipolar disorder in northeastern Algeria

Genes involved in neurotransmitter alteration are implicated in the pathophysiology of bipolar disorder (BD), particularly those belonging to dopaminergic and glutamatergic pathways. This study aimed to investigate the putative association between dopamine beta-hydroxylase (DBH) 19bp insertion/deletion rs72393728 and D-amino acid oxidase activator (DAOA) M23 rs3918342 polymorphisms with bipolar disorder in a population from northeastern Algeria. The case-control research included 95 patients and 148 controls. The salting out method was applied for the extraction of DNA. PCR was performed to genotype DBH rs72393728; genotyping of DAOA rs3918342 was conducted by PCR-RFLP. The findings demonstrated significant variations in genotype (P=0.025) and allele (P=0.0088) frequencies of DBH between cases and controls. However, there was no significant correlation between the two groups for DAOA either in genotype or allele distributions (P=0.54, and P= 0.26, respectively), although a significant association was detected for grandiose delusion and M23 (P=0.0015). The DBH rs72393728 polymorphism is reported here for the first time to be associated with the risk of bipolar disorder, both in the Algerian population and in the scientific literature. Despite there being no direct association for DAOA rs3918342 polymorphism and bipolar disorder, the two polymorphisms showed significant correlations when combined.