Genetics and cardiac anomalies: the heart of the matter

Identification of epigenetic factor KAT2B gene variants for possible roles in congenital heart diseases

Congenital heart disease (CHD) is a group of anatomic malformations in the heart with high morbidity and mortality. The mammalian heart is a complex organ, the formation and development of which are strictly regulated and controlled by gene regulatory networks of many signaling pathways such as TGF-β. KAT2B is an important histone acetyltransferase epigenetic factor in the TGF-β signaling pathway, and alteration in the gene is associated with the etiology of cardiovascular diseases. The aim of this work was to validate whether KAT2B variations might be associated with CHD. We sequenced the KAT2B gene for 400 Chinese Han CHD patients and evaluated SNPs rs3021408 and rs17006625. The statistical analyses and Hardy-Weinberg equilibrium tests of the CHD and control populations were conducted by the software SPSS (version 19.0) and PLINK. The experiment-wide significance threshold matrix of LD correlation for the markers and haplotype diagram of LD structure were calculated using the online software SNPSpD and Haploview software. We analyzed the heterozygous variants within the CDS region of the KAT2B genes and found that rs3021408 and rs17006625 were associated with the risk of CHD.

Congenital heart disease and chromossomopathies detected by the karyotype

OBJECTIVE:

To review the relationship between congenital heart defects and chromosomal abnormalities detected by the karyotype.

DATA SOURCES:

Scientific articles were searched in MEDLINE database, using the descriptors "karyotype" OR "chromosomal" OR "chromosome" AND "heart defects, congenital". The research was limited to articles published in English from 1980 on.

DATA SYNTHESIS:

Congenital heart disease is characterized by an etiologically heterogeneous and not well understood group of lesions. Several researchers have evaluated the presence of chromosomal abnormalities detected by the karyotype in patients with congenital heart disease. However, most of the articles were retrospective studies developed in Europe and only some of the studied patients had a karyotype exam. In this review, only one study was conducted in Latin America, in Brazil. It is known that chromosomal abnormalities are frequent, being present in about one in every ten patients with congenital heart disease. Among the karyotype alterations in these patients, the most important is the trisomy 21 (Down syndrome). These patients often have associated extra-cardiac malformations, with a higher risk of morbidity and mortality, which makes heart surgery even more risky.

CONCLUSIONS:

Despite all the progress made in recent decades in the field of cytogenetic, the karyotype remains an essential tool in order to evaluate patients with congenital heart disease. The detailed dysmorphological physical examination is of great importance to indicate the need of a karyotype.

Pattern of congenital heart diseases in Rwandan children with genetic defects

INTRODUCTION

Congenital heart diseases (CHD) are commonly associated with genetic defects. Our study aimed at determining the occurrence and pattern of CHD association with genetic defects among pediatric patients in Rwanda.

METHODS

A total of 125 patients with clinical features suggestive of genetic defects were recruited. Echocardiography and standard karyotype studies were performed in all patients.

RESULTS

CHDs were detected in the majority of patients with genetic defects. The commonest isolated CHD was ventricular septal defect found in many cases of Down syndrome. In total, chromosomal abnormalities represented the majority of cases in our cohort and were associated with various types of CHDs.

CONCLUSION

Our findings showed that CHDs are common in Rwandan pediatric patients with genetic defects. These results suggest that a routine echocardiography assessment combined with systematic genetic investigations including standard karyotype should be mandatory in patients presenting characteristic clinical features in whom CHD is suspected to be associated with genetic defect.

Gestational and family risk factors for carriers of congenital heart defects in southern Brazil

BACKGROUND

Congenital heart disease (CHD) is a serious threat to public health. Despite this, its etiology is poorly understood and few cardiac teratogens have been defined. The aim of the present study was to identify gestational and family risk factors for CHD in a sample of patients from a pediatric hospital in southern Brazil.

METHODS

A prospective and consecutive sample from subjects with or without CHD, hospitalized at a pediatric intensive care unit, was enrolled. All patients with CHD underwent a GTG-banding karyotype. Chromosomal abnormalities were observed in 47 subjects (15.8%), and these were excluded from the study. The final sample consisted of 250 CHD subjects and 303 controls.

RESULTS

After statistical analysis, using logistic regression, the variables age, rural location, gestational loss, use of anti-hypertensive medication, antibiotics and alcohol in the first trimester of pregnancy were all independently associated with CHD. These results were similar to those of some studies and different from others. It should be noted, however, that, for several variables, the data in the literature as well as the present study were insufficient to determine risk.

CONCLUSIONS

Some differences found may be explained by genetic factors and sociocultural diversity. In contrast, because CHD consists of a heterogeneous group of lesions, the etiology may vary. The standardization of research data and classification of methods for future studies are essential.

Congenital cardiac malformations in neonates with apparently isolated gastrointestinal malformations

BACKGROUND

The association of congenital cardiac malformations (CCM) with malformations of the gastrointestinal tract/abdominal wall is known. Nevertheless, the data presently available are derived from patient populations that include some special conditions known to be associated with a high rate of CCM. The aim of the present study was therefore to determine the incidence of cardiac malformations among neonates with apparently isolated malformations of the gastrointestinal tract/abdominal wall.

METHODS

A total of 201 neonates with apparently isolated gastrointestinal malformations were screened on echocardiography.

RESULT

Thirty-six (17.9%) of the neonates were diagnosed as having a CCM. When the four most frequent gastrointestinal malformations were evaluated, a CCM was diagnosed in 11/69 (15.9%) with anal atresia, in 9/38 (23.7%) with tracheoesophageal fistula/esophageal atresia, in 2/25 (8%) with diaphragmatic hernia and in 5/17 (29.4%) with intestinal atresia. In 11 of 36 patients (30.6%) with CCM, the cardiac problems were hemodynamically significant, requiring anti-congestive and/or surgical treatment.

CONCLUSION

A significant number of neonates with apparently isolated gastrointestinal malformations had CCM. Because almost all patients with malformations of the gastrointestinal tract/abdominal wall require early surgical intervention, they should be evaluated on echocardiography to investigate CCM at the earliest opportunity.

The neonate with congenital heart disease: what the cardiac surgeon needs to know from the neonatologist and the cardiologist

To plan and accomplish a successful operation for a neonate with congenital heart disease, the cardiac surgeon requires a complete anatomic description of the cardiovascular malformation. For optimum outcome, this information must be supplemented by a complete report of the prenatal and postnatal course of the newborn as well as by a thorough summary of any noncardiac congenital or acquired abnormalities. In the most favorable circumstance, the neonate arrives in the operating room completely diagnosed, fully resuscitated, well nourished, and with appropriate monitoring devices in place. Unique perioperative considerations attach to each cardiac anomaly and are briefly reviewed, and the importance of continuity of care for the patient and family is emphasized.

Cardiac conduction abnormalities and congenital immunodeficiency in a child with Kabuki syndrome: case report

Background

Since it's recognition in 1981, a more complete phenotype of Kabuki syndrome is becoming evident as additional cases are identified. Congenital heart defects and a number of visceral abnormalities have been added to the typical dysmorphic features originally described.

Case Report

In this report we describe the clinical course of a child diagnosed with Kabuki syndrome based on characteristic clinical, radiological and morphologic features who died of a cardiac arrhythmia at 11-months of age. This infant, however, had abnormal pulmonary architecture and alterations in his cardiac conduction system resulting in episodes of bradycardia and asystole. This child also had an immunological phenotype consistent with common variable immunodeficiency. His clinical course consisted of numerous hospitalizations for recurrent bacterial infections and congenital hypogammaglobulinemia characterized by low serum IgG and IgA but normal IgM levels, and decreased antibody levels to immunizations. T-, B- and NK lymphocyte subpopulations and T-cell function studies were normal.

Conclusion

This child may represent a more severe phenotype of Kabuki syndrome. Recurrent infections in a child should prompt a thorough immunological evaluation. Additionally, electrophysiology testing may be indicated if cardiopulmonary events occur which are not explained by anatomic defects.