Correlation of plasma dopamine β-hydroxylase activity with polymorphisms in DBH gene:: A study on eastern indian population

Plasma dopamine beta-hydroxylase activity (plD beta H) is tightly regulated by the DBH gene and several genetic polymorphisms have been found to independently exert their influence. In the present investigation, association of four DBH polymorphisms, DBH-STR, rs1611115, rs1108580, and rs2519152 with plD beta H was examined in blood samples from 100 unrelated individuals belonging to the state of West Bengal, Eastern India. Genotypes obtained after PCR amplification and restriction digestion were used for statistical analyses. plD beta H was measured using a photometric assay and its correlation with the genetic polymorphisms was analyzed using analysis of variance and linear regression. Moderate linkage disequilibrium (LD) was observed between DBH-STR and rs1611115, while rs1108580 and rs2519152 were in strong LD. 'T' allele of rs1611115 showed strong negative correlation with plD beta H, whereas DBH-STR, rs1108580 and rs2519152 had no major effect. Four haplotypes showed significant influence on plD beta H. This is the first report on the effect of genetic polymorphisms on plD beta H from the Indian sub-continent. rs1611115 was the only polymorphism that showed substantial control over plD beta H. Other polymorphisms which did not show individual effects could possibly be part of larger haplotype blocks that carry the functional polymorphisms controlling plD beta H.