成人領域では,肥満に影響を及ぼす様々な遺伝子多型が近年発見され,βアドレナリン受容体もその1つである.今回,東医療センター小児科に成長ホルモン治療のため通院している男児27人,女子19人を対象として,1～6歳までの身体所見(身長,体重)縦断的データをβ2,3アドレナリン両遺伝子多型群間で比較検討を行った.日本人に多いとされるβ3アドレナリン受容体遺伝子コドン64の変異群では,非変異群と比較して6歳時までの肥満度(%)が+17.7対+1.3と有意に大きく推移していた.β2コドン16では同様の遺伝子変異による差を認めなかった.就学前という低年齢時より肥満度の差を呈していることから,β3アドレナリン受容体遺伝子多型は本邦における小児肥満の原因の1つであることが示唆された.Over the last years, several single nucleotide polymorphisms influencing early-onset obesity have been characterized. As candidate genes, recent studies have focused on the adrenergic receptor system. A descriptive study using the medical charts of 46 children (19 girls and 27 boys) were of short stature and treated by growth hormone (GH). Anthropometric data of the children were recorded longitudinally from 1 to 6 years of age prior to the commencement of GH treatment. The mean percent overweight increased linearly during the 5-year study period, from -5.3% to 17.7% in the group of children with the mutation of the β3-adrenergic receptor codon 64 polymorphism, and -5.0% to 1.3% in those without this mutation. In contrast, the differences among the subtypes of the β2-adrenergic receptor gene codon 16 polymorphism did not attain statistical significance at any time point during this study. Trp64Arg polymorphism of the β3-adrenergic receptor gene appears to be a genetic risk factor for obesity in Japanese preschool children
