Single nucleotide polymorphism of NKX2-5 gene with sporadic congenital heart disease in Chinese Bai population

Abstract

Background: Congenital heart disease (CHD) is the most common birth abnormality, especially for sporadic CHD. However, the etiology of sporadic CHD is largely unknown. NKX2-5, the earliest sign of cardiac progenitor cell differentiation, plays a key role in cardiac morphogenesis, and the mutation of this gene can cause sporadic CHD.

Purpose: To investigate the association of genetic variations of NKX2-5 with sporadic CHD in Chinese Bai people.

Methods: The whole 2 coding exons and flanking intron sequences of NKX2-5 gene were screened using DNA sequencing in 70 Chinese Bai patients with sporadic CHD and 136 healthy controls.

Results: A novel heterozygous DNA sequence variant (DSV), 1433A>G, was identified in one tetralogy of Fallot (TOF) patient and one persistent left superior vena cava (PLSVC) patient, but none in controls. The frequency of single nucleotide polymorphism (SNP) rs2277923 in CHD group was significantly higher than that in control group. The allele and genotype were associated with the occurrence of CHD.

Conclusion: The novel DSV (1433A>G) may be relevant with TOF and PLSVC, and the SNP rs2277923 of NKX2-5 gene contributes to the risk of sporadic CHD in Chinese Bai people.

Keywords: Chinese Bai people; Congenital heart disease; NKX2-5; single nucleotide polymorphism.

Figure 1

Sequence diagram of novel heterozygous DSV (1433A>G) site. Arrows indicated the mutations. Genotype: Above, AA; below, AG. Green, black, red and blue represented A allele, G allele, T allele and C allele, respectively.

Figure 2

Linkage disequilibrium map (n2: rs2277923; n4: rs3729753; n6: rs703752; n8: 1433A>G).