Copy number variation of GATA4 and NKX2-5 in Chinese fetuses with congenital heart disease

A Pilot Study of Multiplex Ligation-Dependent Probe Amplification Evaluation of Copy Number Variations in Romanian Children with Congenital Heart Defects

Congenital heart defects (CHDs) have had an increasing prevalence over the last decades, being one of the most common congenital defects. Their etiopathogenesis is multifactorial in origin. About 10-15% of all CHD can be attributed to copy number variations (CNVs), a type of submicroscopic structural genetic alterations. The aim of this study was to evaluate the involvement of CNVs in the development of congenital heart defects. We performed a cohort study investigating the presence of CNVs in the 22q11.2 region and GATA4, TBX5, NKX2-5, BMP4, and CRELD1 genes in patients with syndromic and isolated CHDs. A total of 56 patients were included in the study, half of them (28 subjects) being classified as syndromic. The most common heart defect in our study population was ventricular septal defect (VSD) at 39.28%. There were no statistically significant differences between the two groups in terms of CHD-type distribution, demographical, and clinical features, with the exceptions of birth length, weight, and length at the time of blood sampling, that were significantly lower in the syndromic group. Through multiplex ligation-dependent probe amplification (MLPA) analysis, we found two heterozygous deletions in the 22q11.2 region, both in patients from the syndromic group. No CNVs involving GATA4, NKX2-5, TBX5, BMP4, and CRELD1 genes were identified in our study. We conclude that the MLPA assay may be used as a first genetic test in patients with syndromic CHD and that the 22q11.2 region may be included in the panels used for screening these patients.

GATA 4 Deletions Associated with Congenital Heart Diseases in South Brazil

The normal development of the heart comprises a highly regulated machinery of genetic events, involving transcriptional factors. Congenital heart disease (CHD), have been associated with chromosomal abnormalities and copy number variants (CNVs). Our goal was to investigate through the multiplex ligation-dependent probe amplification (MLPA) technique, the presence of CNVs in reference genes for normal cardiac development in patients with CHD. GATA4 , NKX2-5 , TBX5 , BMP4 , and CRELD1 genes and 22q11.2 chromosome region were analyzed in 207 children with CHD admitted for the first time in a cardiac intensive care unit from a pediatric hospital. CNVs were detected in seven patients (3.4%): four had a 22q11.2 deletion (22q11DS) (1.9%), two had a GATA4 deletion (1%) and one had a 22q11.2 duplication (0.5%). No patients with CNVs in the NKX2-5 , TBX5 , BMP4 , and CRELD1 genes were identified. GATA4 deletions appear to be present in a significant number of CHD patients, especially those with septal defects, persistent left superior vena cava, pulmonary artery abnormalities, and extracardiac findings. GATA4 screening seems to be more effective when directed to these CHDs. The investigation of CNVs in GATA4 and 22q11 chromosome region in patients with CHD is important to anticipating the diagnosis, and to contributing to family planning.

Genetic Testing and Pregnancy Outcome Analysis of 362 Fetuses with Congenital Heart Disease Identified by Prenatal Ultrasound

Background

Congenital heart defects (CHD), as the most common congenital anomaly, have been reported to be associated with chromosomal abnormalities. Currently, patients with CHD are routinely offered karyotyping and chromosomal microarray (CMA) testing, but the genotype-phenotype relationship has not yet been fully established.

Objective

To determine the type and frequency of chromosomal abnormalities in fetuses with CHD and to analyze pregnancy outcomes of fetuses with heart abnormalities caused by different genetic factors.

Methods

A total of 362 cases of CHD were enrolled from 2009 to 2016. Detailed ultrasound and laboratory examinations, including karyotyping and CMA, were performed. Outcome was obtained from discharge summaries.

Results

Of the 362 fetuses, 220 were found with an isolated CHD, and 142 had CHD with extracardiac anomaly. Among these 362 fetuses, 140 were identified with a genetic cause, including 111 cases with aneuploidy, 10 cases with abnormality of chromosomal structure by karyotyping and 19 cases with pathogenic or likely pathogenic copy-number variations (CNVs) by CMA. The detection rate is close to 38.7%. Only one (identified as trisomy 18 syndrome) in 140 positive cases resulted in perinatal death, with the others being induced. The remaining 222 cases had negative results for both genetic testing and of these cases, 56 resulted in induced labor, and 77 had natural childbirth or caesarean births. The pregnancy outcome of the remaining 89 cases was uncertain.

Conclusions

Karyotyping and CMA are effective and accurate prenatal genetic techniques for identifying fetal chromosomal abnormalities associated with cardiac defects, and this can assist clinical doctors to perform appropriate genetic counselling with regard to the etiology and outcome of CHD.