内皮细胞一氧化氮合成酶基因多态性和缺血性股骨头坏死的相关性研究

Association of endothelial nitric oxide synthase gene polymorphisms and avascular necrosis of femoral head

目的 观察内皮细胞一氧化氮合成酶（eNOS）基因的内含子4（Intron 4）和外显子7（exon7）等位基因变异和缺血性股骨头坏死（ANFH）发病风险的关系,探索ANFH的遗传易感因素和相关发病机制.方法 无髋关节外伤史的ANFH患者125例,按Ficat标准进行临床诊断和分期,健康人群126例作为对照组.静脉采血提取血细胞基因组DNA,并进行多聚酶链式反应特异性扩增和基因测序,检测eNOS基因Intron 4的27 bp重复序列多态性和exon7的G894T多态性.结果 经基因分析显示ANFH组eNOS内含子4等位基因的b/b型、b/a型、a/a型出现频率为：104/125（83.2％）、19/125（15.2％）、2/125（1.6％）;正常对照组为120/126（95.2％）、6/126（4.8％）、0例（0）.ANFH组的b/a型出现频率明显高于正常对照组（P=0.0001,OR =4.501）.经PCR-RLFP分析eNOS外显子7等位基因的894的G/G野生型、G/T杂合型、T/T纯合突变型的出现频率分别为：ANFH组92/125（73.6％）、30/125（24.0％）、3/125（2.4％）,正常对照组106/126（84.1％）、17/126（13.5％）、3/126（2.4％）;ANFH组的G/T型出现频率明显高于正常对照组（P=0.0094,OR=3.804）.在ANFH组的内含子4序列中,特发性、激素性和酒精性病因的b/a型出现频率分别为11/65（16.9％）、4/27（14.8％）、4/33（12.1％）,其中特发性ANFH患者b/a型出现频率明显高于正常对照组（P=0.0203,OR =2.975）;在ANFH组的外显子7序列中,特发性、激素性和酒精性病因的G/T型出现频率分别为15/65（23.1％）、7/27（23.6％）、8/33（24.2％）,其中特发性ANFH患者G/T型出现频率明显高于正常对照组（P =0.0357,OR =2.205）.结论 内皮细胞一氧化氮合成酶基因的内含子4序列中b/a等位基因的突变使股骨头缺血性坏死的发生率增加,外显子7序列中G894T等位变异也是股骨头缺血坏死的危险因素之一.在产生股骨头缺血性坏死的特发性、激素性、酒精性病因中,内皮细胞一氧化氮合成酶内含子4的b/a等位基因变异和外显子7的G894T变异对特发性股骨头坏死的影响更明显.

Objective To investigate the association of endothelial nitric oxide synthase （eNOS） polymorphisms and avascular necrosis of femoral head （ANFH）,to explore possible relationship between the ANFH incidence and 27-bp repeat polymorphism in intron 4 and G894T polymorphism in exon 7.Methods Totally 125 atraumatic ANFH patients and 126 healthy controls without hip trauma history were enrolled.Gene polymorphisms in 27-bp repeat polymorphism in intron 4 and G894T polymorphism in exon 7 were determined.Medical history was collected for etiology analysis.Results In between-group comparison,the frequency of b/a genotype intron 4 in ANFH group was significantly higher than that in healthy control group [19/125 （15.2%） vs 6/126 （4.8%）,P =0.0001,OR =4.501],and the result of G/T genotype exon 7 in the ANFH group also indicated a statistical significance with the healthy control group [30/125 （24.0%） vs 17/126 （13.5%）,P =0.0094,OR =3.804].In subgroup analysis,genotype b/a and G/T were especially higher in the idiopathic group than that in the healthy control group.Conclusions eNOS gene polymorphisms might be a risk factor of ANFH,there is underlying relevance of eNOS and the disease.Both 27-bp repeat polymorphism in intron 4 and G894T polymorphism in exon 7 are associated with ANFH incidence.