Studying the relation between leptin and adinopectin gene polymorphism and their expressions in patients with down syndrome

ABSTRACT STUDYING THE RELATION BETWEEN LEPTIN AND ADINOPECTIN GENE POLYMORPHISM AND THEIR EXPRESSIONS IN PATIENTS WITH DOWN SYNDROME Down syndrome (DS) is the most frequent chromosomal disease. There are several discussions regarding the necessity of polymorphism and expressions of the genes on the 21st chromosome, the existence of expressions which do not create phenotypic effect, how many genes on the chromosome are related to the syndrome and which of these expressions increase for this syndrome to occur. Obesity prevalence is acknowledged to be higher in patients with DS. An important method in searching through obesity genes is genomic scans. The main function of Leptin (LEP) is to prevent the development of obesity by decreasing appetite. Adinopectin (ADİPOQ) is in a lower level in the obese. Our study was conducted to investigate the relation between leptin, adinopectin gene polymorphism and gene expressions in children with DS who are prone to obesity and to determine whether polymorphism or expression of LEP, LEPR and ADIPOQ genes are an important factor in obesity. Demographic data about the patients, their anthropometric measurements, laboratory values and echocardiography values (ECHO) were recorded. The polymorphisms of LEP, LEPR and ADIPOQ genes in all DS patients and mRNA expression levels of LEP and ADIPOQ genes were assessed. 30 children with DS who we kept track of at Fırat University Medical Faculty Pediatric Health and Diseases Department and 30 healthy children with no chronic diseases as the control group were involved in the study. In our study, the effect of LEP gene -2548G/A, LEPR gene Gln223Arg, ADIPOQ 276G>T gene polymorphism in children with DS was investigated and no relation was found between them. A significant relation was found between ADIPOQ45T>G gene polymorphism and obesity. The connection between leptin gene mRNA expression and obesity in children with Down syndrome was investigated and a significant relation was found. This conclusion supports the fact that there is generally a presence of increased expression in mRNA levels in trisomic genes. However, studying leptin gene mRNA expression by also checking insulin levels will breed positive results. Studying genetic factors that could be effective in obesity in children with DS will help to enlighten this important problem. For this, it is seen that there is a need to find out genetic variations in the population with DS and to clarify the genetic mechanisms of this phenotypic traits. Keywords: Down syndrome, obesity, LEP gene, LEPR gene, ADIPOQ gene