Evaluation of the effect of carboxylestrase-1(CES-1) gene polymorphism on methylphenidate (MPH) treatment in attentiondeficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is among the common disorders of the children. Psychostimulant agents especially methylphenidate (MPH) are among the first line classes in the treatment of ADHD. Among children that are treated with MPH there can be different responses to the treatment one of them being severe side effects due to genetic variations. It has been suggested that single gene polymorphisms (SNPs) in CES-1, LPHN3 and COMT genes could be related with this increased side effect profile. In our study, the genotype distribution of the CES-1 rs71647871, rs3815583 and rs 2307227 polymorphisms, LPHN3 rs6551665, rs6858066, rs1947274, and rs2345039 polymorphisms and COMT rs 4680 was examined in children diagnosed with ADHD and treated with MPH. 5-17 aged children diagnosed with ADHD included to the study. From the saliva samples gen expressions and polymorphisms studied by real time PCR techniques. We found a significant difference between the side effect (+) and side effect (-) groups in terms of genotype distribution of CES-1 (rs 2307227) polymorphism. And these polymorphisms were related with the side effects. In conclusion we have shown that the CES-1 gene is associated with side effect severity of patients treated with methylphenidate. COMT gene polymorphism showed no association with side effect More number of samples for further studies are needed to show relation between side effects and gene polymorphism.