title: Two novel and functional DNA sequence variants within an upstream enhancer of the human NKX2-5 gene in ventricular septal defects.
abstract: Mortality in patients with congenital heart disease (CHD) is significantly increased even with successful surgeries. The main causes are late cardiac complications, such as heart failure and arrhythmia, probably due to genetic defects. To date, genetic causes for CHD remain largely unknown. NKX2-5 gene encodes a highly conserved homeobox transcription factor, which is essential to the heart development in embryos and cardiac function in adults. Mutations in NKX2-5 gene have been implicated in diverse types of CHD, including ventricular septal defect (VSD). As NKX2-5 is a dosage-sensitive regulator, we have speculated that changed NKX2-5 levels may mediate CHD development by influencing cardiac gene regulatory network. In previous studies, we have analyzed the NKX2-5 gene promoter and a proximal enhancer in VSD patients. In the present study, we further genetically and functionally analyzed an upstream enhancer of the NKX2-5 gene in large cohorts of VSD patients (n=340) and controls (n=347). Two novel heterozygous DNA sequence variants (DSVs), g.17483576C>G and g.17483564C>T, were identified in three VSD patients, but none in controls. Functionally, these two DSVs significantly decreased the activity of the enhancer (P<0.01). Another novel heterozygous DSV, g.17483557Ins, was found in both VSD patients and controls with similar frequencies (P>0.05). Taken together, our data suggested that the DSVs within the upstream enhancer of the NKX2-5 gene may contribute to a small number of VSD. Therefore, genetic studies of CHD may provide insight into designing novel therapies for adult CHD patients.
authors: Shandong Provincial Key Laboratory of Cardiac Disease Diagnosis and Treatment, Jining Medical University Affiliated Hospital, Jining Medical University, Jining, Shandong 272029, China.
authors: Wenhui
authors: W
authors: Huang
authors: Haihong
authors: H
authors: Meng
authors: Yuangang
authors: Y
authors: Qiao
authors: Shuchao
authors: S
authors: Pang
authors: Dongfeng
authors: D
authors: Chen
authors: Bo
authors: B
authors: Yan
mesh_terms: D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004742:Enhancer Elements, Genetic; D005260:Female; D057809:HEK293 Cells; D006345:Heart Septal Defects, Ventricular / Q000235:genetics*; D006579:Heterozygote; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D020641:Polymorphism, Single Nucleotide; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D055815:Young Adult
chemical_list: D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C095552:NKX2-5 protein, human; D014157:Transcription Factors