Genetic analysis of the promoter region of the GATA4 gene in patients with ventricular septal defects

Chinese Academy of Medical Sciences, Peping, Beijing, China
Translational research : the journal of laboratory and clinical medicine 05/2012; 159(5):376-82. DOI: 10.1016/j.trsl.2011.10.012
Source: PubMed


Ventricular septal defects (VSDs) are the most common type of congenital heart diseases (CHDs). To date, the genetic causes for sporadic VSDs remain largely unknown. GATA transcription factor 4 (GATA4) is a zinc-finger transcription factor that is expressed in developing heart and adult cardiomyocytes. Mutations in the coding region of the GATA4 gene have been identified in CHD patients, including VSD. As the GATA4 factor is a dosage-sensitive regulator, we hypothesized that the promoter region variants of the GATA4 gene may be genetic causes of VSD. In this study, we analyzed the promoter region of the GATA4 gene by bidirectional sequencing in 172 VSD patients and 171 healthy controls. The results showed that 5 heterozygous sequence variants (NG_008177:g.4071T>C, NG_008177:g.4148C>A, NG_008177:g.4566C>T, NG_008177:g.4653G>T, and NG_008177:g.4690G>deletion) within the promoter region of the GATA gene were identified in 5 VSD patients, but in none of controls. One heterozygous sequence variant (g.4762C>A) was found only in one control, which may have no functional significance. A functional analysis revealed that the transcriptional activity of variant NG_008177:g.4566C>T was reduced significantly, whereas the transcriptional activities of the variants (NG_008177:g.4071T>C, NG_008177:g.4148C>A, NG_008177:g.4653G>T, and NG_008177:g.4690G>deletion) were increased significantly compared with the wild-type GATA4 gene promoter. As GATA4 is a dosage-sensitive regulator during development, our data suggest that these sequence variants within the promoter region of the GATA4 gene may contribute to the VSD etiology by altering its gene expression. Additional studies in experimental animals will deepen our understanding of the genetic basis of VSD and shed light on designing novel molecular therapies for adult VSD patients carrying these variants.

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    ABSTRACT: Congenital heart disease (CHD) is the most common birth defects in humans. The genetic causes for CHD remain largely unknown. T-box transcription factor 1 (TBX1), a dosage-sensitive regulator, plays a critical role in the heart development. Mutations in the coding regions of TBX1 gene have been associated to 22q11 deletion syndrome with cardiac defects and isolated CHD cases, including ventricular septal defect (VSD). To date, TBX1 gene promoter region has not been analyzed and reported in CHD patients. We hypothesized that the sequence variants within TBX1 gene promoter region may change TBX1 levels and mediate CHD development. In this study, the promoter regions of TBX1 gene were genetically and functionally analyzed in 280 VSD patients and 267 healthy controls. Two novel heterozygous variants, g.4353C>T and g.4510A>C, were found in two VSD patients, but in none of controls. The single-nucleotide polymorphism-rs41260844, g.4199T>C, was found more frequent in VSD patients than controls (P < 0.01). Functional analyses revealed that these sequence variants significantly enhanced transcriptional activities of TBX1 gene promoter. Therefore, the sequence variants within TBX1 gene promoter may contribute to the VSD etiology by altering the expression levels of TBX1 gene. Pharmaceutical or genetic manipulation of TBX1 gene expression may provide a novel personalized therapy to prevent and treat late cardiac complications for the adult CHD patients carrying these variants.
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    No preview · Article · Sep 2012 · Biochemical and Biophysical Research Communications
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