目的：探讨瘦素受体基因(LEPR)第20外显子突变对脂质代谢的影响及肥胖儿童基因型与血脂的关系。方法：用聚合酶链反应限制性片段长度多态性(PCRRFLP)方法及聚丙烯酰胺凝胶电泳分析20外显子的基因突变频率,并测定单纯型肥胖儿童(102例)和健康儿童(81例)血清中甘油三脂(TG)、总胆固醇(TC)、高密度脂蛋白(HDL)和低密度脂蛋白(LDL)水平。两组分别测量身高、体重,计算体重指数(BMI)及脂肪百分比。结果：肥胖儿童瘦素受体基因的20外显子经PCRRFLP及聚丙烯酰胺凝胶电泳分析,检测出3种基因型G/G,G/A和A/A型。肥胖儿童20外显子3057位G→A突变频率较健康儿童增高(P<0.05)。A/A基因型的肥胖儿童其血清TG(1.8±0.5mmol/Lvs1.0±0.4mmol/L,P<0.01)、BMI(33±5kg/m2vs25±4kg/m2,P<0.05)水平和脂肪百分比(30±8vs20±3,P<0.01)均明显高于G/G基因型者,而血清HDL水平则低于后者(1.08±0.23mmol/Lvs1.38±0.22mmol/L,P<0.01)。G/A型肥胖儿童,除其血清TG浓度高于G/G基因型者外(1.6±0.4mmol/Lvs1.0±0.4mmol/L,P<0.05),余各项指标均与另外两种基因型无明显差别。心电图检查显示部分A/A型血脂增高儿童有ST段和T波改变。结论：单纯型肥胖儿童瘦素受体基因第20外显子存在基因多态性,且该多态性明显影响肥胖儿童的脂质代谢及体脂分布。该研究为临床上开展对肥胖儿童的早期干预提供了理论依据。

OBJECTIVE: To study the relationship of the variation of the exon 20 of leptin receptor (LEPR) gene with lipid metabolism and fat distribution in children with obesity. METHODS: One hundred and two children with simple obesity (Obesity group) and 81 healthy children (Control group) were enrolled in this study. Polymerase chain reaction-restricted fragments length polymorphism (PCR-RFLP) and polyacrylamide gel electrophoresis were used to analyze the variation of the exon 20 of LEPR gene. The serum levels of triglyceride (TG), total cholesterol (TC), and high density lipoprotein cholesterol (HDL-C) were measured. Body mass index (BMI) and fat percentage (% fat) were calculated. RESULTS: Three genotypes of the exon 20 of LEPR gene were detected:G/G, G/A and A/A. The frequency of the gene variation at 3 057 nucleotide G→A transversion was significantly higher in the Obesity group when compared with the Control group (P<0.05). The levels of serum TG (1.8±0.5 mmol/L vs 1.0±0.4 mmol/L, P<0.01),BMI (33±5 kg/m-2 vs 25±4 kg/m-2, P<0.05) and % fat (30±8 vs 20±3, P<0.01) in obese children with A/A genotype were higher than those of the G/G genotype ones,but the level of serum HDL was lower than that of the G/G genotype patients (1.08±0.23 mmol/L vs 1.38±0.22 mmol/L, P<0.01). As to the G/A genotype patients, only their serum TG levels were higher than those of the G/G genotype ones (1.6±0.4 mmol/L vs 1.0±0.4 mmol/L, P<0.05). The electrocardiography showed the changes of ST segment and T wave in parts of A/ A genotype patients with hyperlipoidemia. CONCLUSIONS: There were polymorphisms in children with obesity and these may affect the lipid metabolism and the fat distribution. The study provided theoretic evidence for the early interference of childhood obesity.