钙调蛋白基因和生长激素受体基因多态性与青少年特发性脊柱侧凸关联性的初步研究

Is polymorphism of CALM1 gene or growth hormone receptor gene associated with susceptibility to adolescent idiopathic scoliosis?

目的研究钙调蛋白基因(CALM1基因)和生长激素受体基因(GHR 基因)在青少年特发性脊柱侧凸(AIS)发病机制中发挥的效应,以及候选基因多态性与 AIS 危险因素是否存在交互效应和基因-基因交互效应。方法采用病例-对照研究方法。AIS 病例组为严格依纳入标准入选的AIS 患者,同时收集相应的性别年龄匹配的对照样本。在获得知情同意后取外周静脉血提取 DNA。选择侯选基因的可疑 SNP 位点,进行 PCR 扩增和基因测序;使用关联分析方法将所得结果进行统计学分析,研究病例与对照组之间的多态性分布差异,以及基因与基因之间的相互关系。根据 AIS 的危险因素设计临床调查问卷,并对所有样本进行调查,将临床资料和实验室结果相结合,研究基因-临床表型之间的关系。结果 AIS 患者具有更高的术后矫正身高和更早的发育高峰时间。CALM1 基因-16C>T 位点 CC 基因型和 GHR 基因 I526L 位点纯合基因型在 AIS 病例组分布频率高于对照组。GHR 基因的 SNP03G-05A、SNP03G-05C 单倍型频率在 AIS 病例组和对照组中频率分布有显著差异,且频率高于10%。GHR 基因 I526L 位点(I526L)的纯合基因型(记为 PP)与褪黑素受体基因 1B 的纯合基因型(记为 GG)组合(记为 PPGG)在 AIS 病例组分布频率显著高于对照组。AIS 病例组 GHR 基因 I526L 位点为纯合基因型患者的术后矫正身高高于杂合型的患者,其发育高峰时间早于杂合型的患者。结论 CALM1基因启动子区的-16C>T 位点 CC 基因型和 GHR 基因的 I526L 位点的纯合基因型可能与 AIS 的易感性相关。

Objective To investigate the major effect of the candidate genes, calmodulin 1 （CALM1） and growth hormone receptor （GHR） gene, in mechanism of adolescent idiopathic scoliosis （.MS） and to evaluate the cross-influence between the polymorphism of the candidates genes and risk factors of AIS. Methods Peripheral blood samples were coUected from 30 AIS patients, 6 boys and 24 girls, aged 15.7, and 30 gender and age-matched controls. Genomic DNA was extracted. PCR amplification and sequencing of the segments containing SNPs chosen from candidate genes were conducted. The SNPs were genotyped then. Statistical analysis was conducted. Questionnaire survey was conducted in terms of the risk factors. Results （ 1 ） The AIS patients had higher corrected standing height and an earlier growth spurt than the controls. （2） The frequencies of CC genotype of CALM1 gene at - 16C 〉 T locus and homozygous genotype of GHR gene at exon 10 I526L were significantly higher in the AIS patients than in the controls. （3） The frequencies of SNP03G-05A and SNP03G-05C haplotypes of GHR gene were significantly higher in the MS patients than in the controls. （4） The frequency of PPGG（ PP = homozygous genotype of GHR gene at 1526L, GG = homozygous genotype of MTNR1B gene at rs1562444 locus ） of the AIS patients was significantly higher than that of the controls. （5） The AIS patients who had homozygous genotype of GHR gene at 1526L had an earlier growth spurt and higher standing height than those who had heterozygous genotype. Conclusion The - 16C 〉 T polymorphism at the promoter region of CALM1 gene and thehomozygous genotype of GHR gene at I526L may be associated with high susceptibility to AIS.