The role of functional polymorphisms of HTT-LPR and COMT in the occurrence of irritable bowel syndrome amongst children

【Objective】 The study was aimed to assess the role of polymorphisms of HTT-LPR and COMT genes in the occurrence of IBS with a glance to the psychoemotional state of children.【Method】 The study was conducted in the gastroenterology department of children clinical hospital № 1 named after B.Y.Reznik(Odessa,Ukraine).There were examined 122 children with IBS at the age of 6 to 17 years.Molecular genetic studies were performed in a specialized laboratory of the Center of Molecular and Genetic Medicine of ONMedU.The samples of genetic material were taken by using non-invasive methods.DNA was extracted using the bisulfate method.Genotyping was performed by PCR using specific oligonucleotide primers.The characteristics of mental and emotional state of children were tested by the questionnaire of "Profile of psychosomatic orientation".Statistical analysis was performed using nonparametric methods with software Statistics 8.0(StatSoft Inc.,USA).【Result】 There was demonstrated that the frequency of homozygote variant of СОМТ*2 polymorphism was 14.8%,and by 5-HTTLPR polymorphism-9.8%.Children suffering IBS has these genotypes in every third case whereas the severity anxiety is correlated with the presence of these functional polymorphisms.The presence of mutant alleles in the homozygous state is closely correlated with the severity of anxiety in children suffering IBS(r =0.84 P <0.01).【Conclusion】 IBS occurrence and anxiety severity is correlated with the presence of functional polymorphisms of HTT-LPR and COMT genes.