ObjectiveTo observe the mutation and expression of Nkx2.5 in congenital heart disease patients with diminutive pulmonary blood. We preliminarily explored the association between Nkx2.5 gene and pathogenesis of congenital heart disease patients with diminutive pulmonary blood. MethodsFifty six patients of congenital heart disease with diminutive pulmonary blood in the first affiliated hospital of Bengbu medical college and Anhui province children, s hospital between May 2012 and May 2014 were as an experimental group. Sixty three patients of ventricular septal defect were as a control group. In the trial group, there were 30 males and 26 females averagely aged 5.82± 4.23 years ranking from 6 months to 14 years. In the control group, there were 36 males and 27 females averagely aged 6.93± 4.56 years ranking from 6 months to 14 years. Before operation, peripheral venous blood of all the patients were collected. We used polymerase chain reaction combined with DNA sequencing technology to detect Nkx2.5 gene exon sequence and to analyze the association between Nkx2.5 gene mutation and congenital heart disease with diminutive pulmonary blood. And we got some hypertrophic myocardial tissue from right ventricular outflow tract in the operation, whose size was 0.5× 0.5× 0.5 cubic centimeter. And we extracted myocardial tissue RNA. The expression changes of Nkx2.5 gene mRNA were detected by real-time fluorescence quantitative polymerase chain reaction technique. ResultsThere was no mutations tested out in the peripheral venous blood in both two groups. The expression of mRNA in Nkx2.5 gene of the trial group was lower than that in the control group with a statistical difference. ConclusionNkx2.5 gene mutation may be associated with multiple factors. The occurrence of congenital heart disease with diminutive pulmonary blood may be related with a decline of Nkx2.5 gene expression in the myocardial tissue.