Nkx2.5在肺血减少型先天性心脏病右室流出道心肌中突变及表达的意义

目的 观察Nkx2.5基因在肺血减少型先天性心脏病（CHD）患者中的突变及表达变化,探讨Nkx2.5基因在右室流出道梗阻发生中的分子调控机制.方法 选取2012年5月—2013年5月蚌埠医学院第一附属医院与安徽省立儿童医院心脏外科收治的56例肺血减少型CHD患者为实验组,同期收治的63例室间隔缺损患者为对照组.收集所有患者术前外周静脉血5 ml,采用PCR结合DNA测序技术对Nkx2.5基因的外显子进行序列检测,观察有无Nkx2.5基因突变;留取术中右室流出道肥厚心肌组织0.5 cm ×0.5 cm ×0.5 cm,提取心肌组织RNA,应用实时荧光定量PCR技术检测心肌中Nkx2.5基因mRNA的表达情况,分析Nkx2.5基因与肺血减少型CHD的关系.结果 实验组与对照组外周静脉血中均未检测出基因突变,实验组心肌组织Nkx2.5基因mRNA表达水平较对照组显著降低,差异有统计学意义（P＜0.01）.结论 Nkx2.5基因突变可能与多因素有关;肺血减少型CHD的发生可能与心肌组织中Nkx2.5基因表达下降有关.

Mutation and expression of Nkx2.5 in the right ventricular outflow tract myocardial of congenital heart disease with diminutive pulmonary blood

Objective To observe the mutation and expression of Nkx2.5 in congenital heart disease（CHD） with diminutive pulmonary blood,and to explore the association between Nkx2.5 gene and pathogenesis of CHD with diminutive pulmonary blood.Methods From May 2012 to May 2013,56 cases of CHD with diminutive pulmonary blood from our department and Anhui Province Children Hospital were selected as the experimental group,63 cases of ventricular septal defect were treated as control group.All patients were collected peripheral venous blood and hypertrophic myocardial tissue from right ventricular outflow tract in the operation,whose size was 0.5 cm × 0.5 cm × 0.5 cm cubic centimeter.Polymerase chain reaction combined with DNA sequencing technology was used to detect Nkx2.5 gene exon sequence,and whether Nkx2.5 gene mutation was associated with CHD with diminutive pulmonary blood was analyzed.Extraction of myocardial tissue RNA,the expression changes of Nkx2.5 gene mRNA was detected by real-time fluorescence quantitative polymerase chain reaction technique and made a statistical analysis between the two groups.Results Fifty-six cases of the experimental group and 63 cases of control group were not detected by Nkx2.5 gene mutations in the peripheral venous blood.The expression level in the experimental group about myocardial Nkx2.5 genes mRNA was significantly reduced compared with the control group,the difference was statistically significant （P 〈 0.01）.Conclusions The Nkx2.5 gene mutation may be associated with multiple factors,the occurrence of CHD with diminutive pulmonary blood may be related with decline of Nkx2.5 gene expression in the myocardial tissue.