Increased incidence of Hirschsprung's disease in patients with hypoplastic left heart syndrome--a common neural crest-derived etiology?

Associated congenital heart disease with Hirschsprung's disease: a retrospective cohort study on 2,174 children

Objective

To examine the incidence and phenotypes of congenital heart disease (CHD) in a large cohort of patients with Hirschsprung's disease (HSCR).

Study design

Retrospective data review of children with HSCR between 2003 and 2020 was conducted at the Provincial Key Laboratory for Structural Birth Defects in Guangzhou, Guangdong, China. HSCR was confirmed by pathological diagnosis. CHD was defined as a gross structural abnormality of the heart or intrathoracic great vessels that is of functional significance.

Results

A total of 2,174 HSCR patients (84.7% males) were studied and 306 of them underwent echocardiography. Overall, 27 children (1.2%) had associated CHD. Among them, CHDs mostly presented as atrial and ventricular septal defects (n = 5 and 12 respectively) and patent ductus arteriosus (n = 4). Three patients (1.4‰) presented as a severe CHD including complete atrioventricular canal, congenitally corrected transposition of the great arteries and double-outlet of right ventricle. Among 14 patients carrying a chromosomal abnormality, CHD was detected in 4 infants (28.6%), all being mild forms of septal defects.

Conclusions

Some new and severe types of CHD were found in patients with HSCR. Patients with syndromic features had higher incidence of CHD.

ETS1 loss in mice impairs cardiac outflow tract septation via a cell migration defect autonomous to the neural crest

Ets1 deletion in some mouse strains causes septal defects and has been implicated in human congenital heart defects in Jacobsen syndrome, in which one copy of the Ets1 gene is missing. Here, we demonstrate that loss of Ets1 in mice results in a decrease in neural crest (NC) cells migrating into the proximal outflow tract cushions during early heart development, with subsequent malalignment of the cushions relative to the muscular ventricular septum, resembling double outlet right ventricle (DORV) defects in humans. Consistent with this, we find that cultured cardiac NC cells from Ets1 mutant mice or derived from iPS cells from Jacobsen patients exhibit decreased migration speed and impaired cell-to-cell interactions. Together, our studies demonstrate a critical role for ETS1 for cell migration in cardiac NC cells that are required for proper formation of the proximal outflow tracts. These data provide further insights into the molecular and cellular basis for development of the outflow tracts, and how perturbation of NC cells can lead to DORV.

Dissection, Culture and Analysis of Primary Cranial Neural Crest Cells from Mouse for the Study of Neural Crest Cell Delamination and Migration

Over the past several decades there has been an increased availability of genetically modified mouse models used to mimic human pathologies. However, the ability to study cell movements and differentiation in vivo is still very difficult. Neurocristopathies, or disorders of the neural crest lineage, are particularly challenging to study due to a lack of accessibility of key embryonic stages and the difficulties in separating out the neural crest mesenchyme from adjacent mesodermal mesenchyme. Here, we set out to establish a well-defined, routine protocol for the culture of primary cranial neural crest cells. In our approach we dissect out the mouse neural plate border during the initial neural crest induction stage. The neural plate border region is explanted and cultured. The neural crest cells form in an epithelial sheet surrounding the neural plate border, and by 24 h after explant, begin to delaminate, undergoing an epithelial-mesenchymal transition (EMT) to become fully motile neural crest cells. Due to our two-dimensional culturing approach, the distinct tissue populations (neural plate versus premigratory and migratory neural crest) can be readily distinguished. Using live imaging approaches, we can then identify changes in neural crest induction, EMT and migratory behaviors. The combination of this technique with genetic mutants will be a very powerful approach for understanding normal and pathological neural crest cell biology.

Nucleic acid methylation and orofacial morphogenesis

In this review, we highlight the current state of knowledge of the diverse roles nucleic acid methylation plays in the embryonic development of the orofacial region and how aberrant methylation may contribute to orofacial clefts. We also consider the role of methylation in the regulation of neural crest cell function as it pertains to orofacial ontogeny. Changes in DNA methylation, as a consequence of environmental effects, have been observed in the regulatory regions of several genes, potentially identifying new candidate genes for orofacial clefting and opening promising new avenues for further research. While the focus of this review is primarily on the nonsyndromic forms of orofacial clefting, syndromic forms are briefly discussed in the context of aberrant nucleic acid methylation.

Epigenetic Mechanisms in Hirschsprung Disease

Hirschsprung disease (HSCR, OMIM 142623) is due to a failure of enteric precursor cells derived from neural crest (EPCs) to proliferate, migrate, survive or differentiate during Enteric Nervous System (ENS) formation. This is a complex process which requires a strict regulation that results in an ENS specific gene expression pattern. Alterations at this level lead to the onset of neurocristopathies such as HSCR. Gene expression is regulated by different mechanisms, such as DNA modifications (at the epigenetic level), transcriptional mechanisms (transcription factors, silencers, enhancers and repressors), postranscriptional mechanisms (3′UTR and ncRNA) and regulation of translation. All these mechanisms are finally implicated in cell signaling to determine the migration, proliferation, differentiation and survival processes for correct ENS development. In this review, we have performed an overview on the role of epigenetic mechanisms at transcriptional and posttranscriptional levels on these cellular events in neural crest cells (NCCs), ENS development, as well as in HSCR.

Hypoplastic Left Heart Syndrome: A New Paradigm for an Old Disease?

Hypoplastic left heart syndrome occurs in up to 3% of all infants born with congenital heart disease and is a leading cause of death in this population. Although there is strong evidence for a genetic component, a specific genetic cause is only known in a small subset of patients, consistent with a multifactorial etiology for the syndrome. There is controversy surrounding the mechanisms underlying the syndrome, which is likely due, in part, to the phenotypic variability of the disease. The most commonly held view is that the “decreased” growth of the left ventricle is due to a decreased flow during a critical period of ventricular development. Research has also been hindered by what has been, up until now, a lack of genetically engineered animal models that faithfully reproduce the human disease. There is a growing body of evidence, nonetheless, indicating that the hypoplasia of the left ventricle is due to a primary defect in ventricular development. In this review, we discuss the evidence demonstrating that, at least for a subset of cases, the chamber hypoplasia is the consequence of hyperplasia of the contained cardiomyocytes. In this regard, hypoplastic left heart syndrome could be viewed as a neonatal form of cardiomyopathy. We also discuss the role of the endocardium in the development of the ventricular hypoplasia, which may provide a mechanistic basis for how impaired flow to the developing ventricle leads to the anatomical changes seen in the syndrome.

Noncompaction cardiomyopathy in Hirschsprung's disease: a case report

Noncompaction cardiomyopathy is a rare disorder, often associated with cardiac and noncardiac malformations. Hirschsprung's disease, a well-known aganglionosis, is associated with congenital heart diseases and has been reported to be due to impairment migration and differentiation of neural crest cells. Here, we present an 8-month-old male infant who died for cardiogenic shock after surgical resection of the involved bowel segment. The child was affected by both noncompaction cardiomyopathy and Hirschsprung's disease, two entities which can share a common neural crest-derived etiology.

Epigenetics in ENS development and Hirschsprung disease

Hirschsprung disease (HSCR, OMIM 142623) is a neurocristopathy caused by a failure of the enteric nervous system (ENS) progenitors derived from neural crest cells (NCCs), to migrate, proliferate, differentiate or survive to and within the gastrointestinal tract, resulting in aganglionosis in the distal colon. The formation of the ENS is a complex process, which is regulated by a large range of molecules and signalling pathways involving both the NCCs and the intestinal environment. This tightly regulated process needs correct regulation of the expression of ENS specific genes. Alterations in the expression of these genes can have dramatic consequences. Several mechanisms that control the expression of genes have been described, such as DNA modification (epigenetic mechanisms), regulation of transcription (transcription factor, enhancers, repressors and silencers), post-transcriptional regulation (3'UTR and miRNAs) and regulation of translation. In this review, we focus on the epigenetic DNA modifications that have been described so far in the context of the ENS development. Moreover we describe the changes that are found in relation to the onset of HSCR.

Griscelli Syndrome Type 3: Two New Cases and Review of the Literature

A 3-year-old Arab boy with a history of hypoplastic left heart syndrome was referred to the pediatric dermatology clinic at Sheba Medical Center for evaluation of hypomelanosis, manifested by fair skin pigmentation and silvery-grey hair, eyebrows, and eyelashes. The child had one older brother with similar hypopigmentation and another older brother who had died of congenital heart disease. The child had no history of neurologic deficits or immunodeficiency and no additional findings on clinical evaluation.

Epigenetic regulation in neural crest development

The neural crest is a migratory and multipotent cell population that plays a crucial role in many aspects of embryonic development. In all vertebrate embryos, these cells emerge from the dorsal neural tube then migrate long distances to different regions of the body, where they contribute to formation of many cell types and structures. These include much of the peripheral nervous system, craniofacial skeleton, smooth muscle, and pigmentation of the skin. The best-studied regulatory events guiding neural crest development are mediated by transcription factors and signaling molecules. In recent years, however, growing evidence supports an important role for epigenetic regulation as an additional mechanism for controlling the timing and level of gene expression at different stages of neural crest development. Here, we summarize the process of neural crest formation, with focus on the role of epigenetic regulation in neural crest specification, migration, and differentiation as well as in neural crest related birth defects and diseases.

A prospective observational study of associated anomalies in Hirschsprung's disease

BACKGROUND

Associated anomalies have been reported in around 20% of Hirschsprung patients but many Authors suggested a measure of underestimation. We therefore implemented a prospective observational study on 106 consecutive HSCR patients aimed at defining the percentage of associated anomalies and implementing a personalized and up-to-date diagnostic algorithm.

METHODS

After Institutional Ethical Committee approval, 106 consecutive Hirschsprung patients admitted to our Institution between January 2010 and December 2012 were included. All families were asked to sign a specific Informed Consent form and in case of acceptance each patient underwent an advanced diagnostic algorithm, including renal ultrasound scan (US), cardiologic assessment with cardiac US, cerebral US, audiometry, ENT and ophthalmologic assessments plus further specialist evaluations based on specific clinical features.

RESULTS

Male to female ratio of our series of patients was 3,4:1. Aganglionosis was confined to the rectosigmoid colon (classic forms) in 74,5% of cases. We detected 112 associated anomalies in 61 (57,5%) patients. The percentage did not significantly differ according to gender or length of aganglionosis. Overall, 43,4% of patients complained ophthalmologic issues (mostly refraction anomalies), 9,4% visual impairment, 20,7% congenital anomalies of the kidney and urinary tract, 4,7% congenital heart disease, 4,7% hearing impairment or deafness, 2,3% central nervous system anomalies, 8,5% chromosomal abnormalities or syndromes and 12,3% other associated anomalies.

CONCLUSIONS

Our study confirmed the underestimation of certain associated anomalies in Hirschsprung patients, such as hearing impairment and congenital anomalies of the kidney and urinary tract. Subsequently, based on our results we strongly suggest performing renal US and audiometry in all patients. Conversely, ophthalmologic assessment and cerebral and heart US can be performed according to guidelines applied to the general population or in case of patients with suspected clinical features or chromosomal abnormalities. This updated diagnostic algorithm aims at improving overall outcome thanks to better prognostic expectations, prevention strategies and early rehabilitation modalities. The investigation of genetic background of patients with associated anomalies might be the next step to explore this intriguing multifactorial congenital disease.

Sudden unexpected early neonatal death due to undiagnosed Hirschsprung disease enterocolitis: a report of two cases and literature review

Hirschsprung enterocolitis (HEC) is an uncommon, albeit well known, complication of Hirschsprung disease (HD). It is multifactorial and can appear in different age groups, but is particularly important in the neonatal period where it is characteristically seen in full-term neonates. Two cases of HEC are reported that were diagnosed at post-mortem examination, which presented as early sudden neonatal death, with a review the literature on fatal Hirschsprung enterocolitis. Case 1 was a 4-day old male neonate who was found unwell, struggling to breath, and with green vomitus. He was taken to hospital and pronounced dead a short time later. According to the parents meconium was passed on the first day. Post-mortem examination demonstrated necrotizing enterocolitis with isolated bowel perforation. Histology disclosed unsuspected HD. Case 2 was a 2-day old male neonate who was found wheezing with green vomitus. He arrived floppy, cyanosed, and in shock at the hospital and died a few hours later. Meconium was not passed, according to the parents. Post-mortem examination revealed necrotizing enterocolitis. There was also recto-sigmoidal aganglionosis and acetylcholinesterase staining confirmed HD. HEC is a multifactorial and sometimes recurrent complication of HD which characteristically develops in full-term neonates. Presentation with early sudden neonatal death is rare but should be considered in the diagnostic work-up of sudden deaths in this age group.

Long-term outcomes of Hirschsprung's disease

Despite significant developments in the understanding of the pathologic anatomy and physiology of Hirschsprung's disease (HD), the results of surgical therapy remain far from perfect. The functional defects and psychosocial difficulties that occur commonly in children with HD are passed on to adulthood in a significant proportion of patients. Recent prospective and adequately controlled cross-sectional studies reveal that constipation and fecal soiling are common late sequelae in adulthood. HD patients show uniformly lower scores of overall bowel function than healthy control subjects. Functional outcome and quality of life may be interrelated and deteriorate with increasing age. Despite these shortcomings, at adult age, most of the HD patients appear to be able to function as normal members of the society in terms of psychosocial, occupational, and recreational activities. Patients are at risk of developing related conditions, such as cancer, that require planning of specific screening programs. Many of the long-term problems that these patients experience are specific to HD. The follow-up of HD patients should be performed by medical personnel familiar with the disease, preferably in a specialized referral center, and the follow-up should continue beyond childhood.

Patients with univentricular heart in early childhood: parenting stress and child behaviour

AIMS

To assess perceptions of child behaviour and parenting stress among the parents of young children with hypoplastic left heart syndrome (HLHS) and other forms of functionally univentricular heart defects (UVH).

METHODS

As part of our prospective nation-wide neurodevelopmental follow-up study, the parents of 23 patients with HLHS, 14 with UVH and 46 healthy controls at the mean age of 18 months received the questionnaires Child Behavior Checklist and Parenting Stress Index.

RESULTS

The reported level of total parenting stress was significantly higher among the mothers (mean score 241 vs 205, p < 0.001) and fathers (235 vs 202, p = 0.003) of patients with HLHS compared with those of controls. The parents of patients with HLHS reported significantly more total (mean T score 52 vs 45, p = 0.005) and internalizing (51 vs 41, p < 0.001) behaviour problems than the controls, but among the syndrome scales, a significant difference was only found in somatic complaints. The parents of patients with UVH did not report more parenting stress or emotional problems than the controls.

CONCLUSION

Hypoplastic left heart syndrome, a severe congenital heart defect, increases parenting stress. The reported emotional maladjustment in affected children might in part be owing to somatic complaints.