瘦素受体外显子突变与ACE基因联合作用对肥胖儿童血脂的影响

Combined effects of variation of exon of leptin receptor and the angiotensin-converting enzyme gene on blood lipid of obese children

目的探讨瘦素受体(LEPR)外显子突变与血管紧张素转换酶(ACE)基因(I/D)多态性联合作用对肥胖儿童血脂的影响。方法选择肥胖儿童116例(肥胖组)和非肥胖的健康儿童78例(健康组)为研究对象。空腹12 h后抽取静脉血。用聚合酶链反应-限制性片段多态性(PCR-RFLP)方法及聚丙烯凝胶电泳分析瘦素受体第20外显子的基因频率及其突变频率,对ACE基因型进行分析。测定血清总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)的水平。于相同条件下测身高、体质量,计算BMI。结果瘦素受体基因第20外显子检出3种基因型,分别为A/A型、G/A型、G/G型。肥胖儿童较健康儿童LEPR基因第20外显子第3057位G→A突变频率增高;ACE基因共检出3种基因型,分别为DD、DI、II。肥胖组比健康组D等位基因检出率高;两者对肥胖儿童脂质代谢均有影响,且有一定的协同作用,表现为LEPR基因型为A/A的肥胖个体中携带D等位基因的儿童更易发生血脂代谢异常。结论肥胖儿童较健康儿童LEPR基因第20外显子第3057位G→A突变频率增高,且D等位基因检出率高;两者对肥胖儿童脂质代谢均有影响,且有一定的协同作用。

Objective To investigate the combined effects of variation of exon of leptin receptor （LEPR） and the angiotensin-converting enzyme （ACE） gene on blood lipid of obese children. Methods A total of 116 obese children and 78 healthy children were recruited. Blood was drawn after fasting over 12 hours. The variation of the exon 20 of LEPR and ACE gene were analyzed by polymerase chain reation-restricted fragments length polymorphism （PCR-RFLP） and polyacrylamide gel electrophoresis. The blood lipid, height and weight were measured. Results The exon 20 of LEPR gene had three genotypes, A/A, G/A, and G/G. Compared with healthy group, the frequency of the gene variation at 3057 nucleotide G→A transversion was higher in obese group. ACE gene had three genotype, DD, DI and II. Compared with healthy group, the frequency of D allele of ACE gene was higher in obese group. The variation of both exon 20 of LEPR and ACE had effect on the lipid metabolism, and had synergies. The obese children with LEPR A/A genotype and carrying D allele are more susceptible to abnormal lipid metabolism. Conclusions The frequency of the gene variation at 3057 nucleotide G→A transversion, and the D allele of the ACE gene were higher in obese children than those in healthy children. The variation of both genes had combined effects on the lipid metabolism.