A novel NKX2.6 mutation associated with congenital ventricular septal defect

Area of Science:

• Cardiovascular Genetics
• Developmental Biology
• Medical Genetics

Background:

• Congenital heart disease (CHD) is a leading cause of infant mortality, with genetic factors playing a significant role.
• Despite evidence of genetic involvement, the specific genetic determinants for most CHD cases remain unidentified.
• NKX2.6 is a critical transcription factor for cardiovascular development, but its role in CHD pathogenesis is largely unknown.

Purpose of the Study:

• To investigate the role of the NKX2.6 gene in the etiology of congenital heart disease, specifically ventricular septal defects (VSD).
• To identify novel genetic mutations in NKX2.6 associated with isolated VSD.
• To functionally characterize the identified NKX2.6 mutation to understand its impact on cardiovascular development.

Main Methods:

• Sequencing of the NKX2.6 gene in 210 unrelated patients with CHD.
• Genetic analysis of familial segregation for identified mutations.
• Functional assessment of the mutation's effect on transcriptional activity using NKX2.5 as a surrogate model.

Main Results:

• A novel heterozygous NKX2.6 mutation (p.K152Q) was identified in a patient with VSD.
• The mutation cosegregated with VSD in the family, indicating an autosomal dominant inheritance pattern with complete penetrance.
• Functional analysis revealed that the p.K152Q mutation impairs NKX2.6's transcriptional activity, similar to a known mutation in the related NKX2.5 gene.

Conclusions:

• This study establishes a link between NKX2.6 loss-of-function mutations and an increased susceptibility to isolated VSD.
• The findings provide new molecular insights into the pathogenesis of VSD, a common form of CHD.
• This research may contribute to the development of novel diagnostic, preventive, and therapeutic strategies for VSD and other CHDs.