Familial Hirschsprung's disease: report of autosomal dominant and probable recessive X-linked kindreds

Comprehensive characterization of the genetic landscape of familial Hirschsprung's disease

BACKGROUND

Hirschsprung's disease (HSCR) is one of the most common congenital digestive tract malformations and can cause stubborn constipation or gastrointestinal obstruction after birth, causing great physical and mental pain to patients and their families. Studies have shown that more than 20 genes are involved in HSCR, and most cases of HSCR are sporadic. However, the overall rate of familial recurrence in 4331 cases of HSCR is about 7.6%. Furthermore, familial HSCR patients show incomplete dominance. We still do not know the penetrance and genetic characteristics of these known risk genes due to the rarity of HSCR families.

METHODS

To find published references, we used the title/abstract terms "Hirschsprung" and "familial" in the PubMed database and the MeSH terms "Hirschsprung" and "familial" in Web of Science. Finally, we summarized 129 HSCR families over the last 40 years.

RESULTS

The male-to-female ratio and the percentage of short segment-HSCR in familial HSCR are much lower than in sporadic HSCR. The primary gene factors in the syndromic families are ret proto-oncogene (RET) and endothelin B receptor gene (EDNRB). Most families show incomplete dominance and are relevant to RET, and the RET mutation has 56% penetrance in familial HSCR. When one of the parents is a RET mutation carrier in an HSCR family, the offspring's recurrence risk is 28%, and the incidence of the offspring does not depend on whether the parent suffers from HSCR.

CONCLUSION

Our findings will help HSCR patients obtain better genetic counseling, calculate the risk of recurrence, and provide new insights for future pedigree studies.

Familial Near-Total Intestinal Aganglionosis

Near total aganglionosis represents the most extreme and rare form of Hirschsprung's disease. It can affect more than one member of family. We report three cases of near total intestinal aganglionosis in a family presenting with intestinal obstruction at birth. All of them were operated and a jejunostomy was performed. Outcome was dismal.

Hirschsprung's disease in twins: a systematic review and meta-analysis

AIM OF THE STUDY

Hirschsprung's disease (HSCR) is known to occur in families. The reported overall incidence of familial cases is 7.6%, with a higher incidence of 15-21% in total colonic aganglionosis and 50% in the rare total intestinal aganglionosis. HSCR is extremely rare in twins. The aim of this study was to systematically analyse the patterns of HSCR in twins published in the literature.

METHODS

Electronic databases Pubmed and Medline were screened for relevant articles using the keywords "Hirschsprung's disease", "aganglionosis", "twins", "monozygotic", and "dizygotic". Examining reference lists identified further relevant papers.

MAIN RESULTS

Twelve studies with a total of 18 twin pairs were included in this analysis. 67% twins were discordant. HSCR was found in 24 out of 36 twin subjects (67%), of which 83% affected were male. Rectosigmoid type was reported in 71% of patients, long-segment disease in 21, and 8% presented with a total aganglionosis. Three twin pairs had at least one family member affected with HSCR.

CONCLUSION

HSCR was found in two-thirds of twin subjects with a male predominance. Rectosigmoid aganglionosis was the most common variant. Disease discordance was identified, where environmental insults were postulated to be predisposing factors to disease expression. Future studies investigating the disease-associated mutations in the already identified HSCR genes should provide insights into the genetic basis of HSCR in twins.

Growth and developmental outcomes of infants with hirschsprung disease presenting in the neonatal period: a retrospective study

OBJECTIVES

To describe the presentation and progress over the first year of life of neonates with Hirschsprung disease, to describe their physical and developmental outcomes at 12 months of age, and to compare the outcomes of infants with short- vs long-segment Hirschsprung disease.

STUDY DESIGN

A retrospective study of neonates born with Hirschsprung disease in Western Australia between January 1, 2001, and December 31, 2010, to review their presentation, progress, growth, and development at 12 months of age.

RESULTS

Fifty-four infants were identified (40 with short and 11 with long segment and 3 with total colonic aganglionosis); 9 infants had a recognized syndrome and 1 infant died, unrelated to Hirschsprung disease. A primary pull-through procedure was performed in 97% and 21% of neonates with short- and non-short-segment Hirschsprung disease, respectively; 17 (31%) infants developed anal stenosis requiring dilatations. Enterocolitis occurred in 14 (26%) infants. Griffiths Mental Development Scale scores (1 year) were available in 31 of 45 nonsyndromic survivors: mean general quotient (94.2, SD 8.89) was significantly less than the population mean (P = .007), but the number of infants with developmental delay was within the expected range. Physical growth, except length, appeared adequate in nonsyndromic infants. There were no significant differences in the outcomes of infants with short- vs non-short-segment Hirschsprung disease.

CONCLUSIONS

At 1 year of age, many infants with Hirschsprung disease have ongoing gastrointestinal problems. Their overall growth appears satisfactory, and most infants are developing normally; however, their mean general quotient appears shifted to the left. Longer-term studies will better define developmental outcomes.

Neuropathology of paediatric chronic intestinal pseudo-obstruction and related animal models

Chronic intestinal pseudo-obstruction (CIP) in paediatric patients is due to heterogeneous aetiologies that include primary disorders of the enteric nervous system. These conditions are poorly delineated by contemporary diagnostic approaches, in part because the complex nature of the enteric nervous system may shelter significant physiological defects behind subtle or quantitative anatomical changes. Until recently, relatively few experimental animal models existed for paediatric CIP. However, the availability of rodent models, particularly novel mutants created in the last few years by genetic manipulations, has brought unprecedented opportunities to investigate molecular, cellular, physiological, and histological details of enteric neuropathology. Information gleaned from studies of these animals is likely to change diagnostic and therapeutic approaches to paediatric CIP and related conditions.

Hirschsprung disease and other enteric dysganglionoses

Hirschsprung disease has become a paradigm for multigene disorders because the same basic phenotype is associated with mutations in at least seven distinct genes. As such, the condition poses distinct challenges for clinicians, patients, diagnostic pathologists, and basic scientists, who must cope with the implications of this genetic complexity to comprehend the pathogenesis of the disorder and effectively manage patients. This review focuses on the anatomic pathology, genetics, and pathogenesis of Hirschsprung disease and related conditions. The nature and functions of "Hirschsprung disease genes" are examined in detail and emphasis is placed on the importance of animal models to this field. Where possible, potential uses and limitations of new data concerning molecular genetics and pathogenesis are discussed as they relate to contemporary medical practices.

Hirschsprung's disease: a search for etiology

In 1967, Okamoto et al suggested that the absence of ganglion cells in Hirschsprung's disease (HD) was attributable to failure of migration of neural crest cells. The earlier the arrest of migration, the longer the aganglionic segment. Since then, this hypothesis generally has been accepted. However, subsequent experiments using mouse models of intestinal aganglionosis indicate that nerve cells may reach the correct position but then fail to develop or survive. An alternative hypothesis has been proposed that the aganglionosis may be caused by failure of differentiation as a result of microenvironmental changes after the migration has occurred. Extracellular matrix proteins are recognized as important microenvironmental factors. It has been shown that enteric neurogenesis is dependent on extracellular matrices, which provide a migration pathway for neural crest-derived cells and promote the maturation of settled neural crest-derived cells. Altered distributions of extracellular matrices have been shown in human HD cases and murine HD models, suggesting the role of extracellular matrices in the pathogenesis of HD. Recent studies suggest that intestinal smooth muscle cells, target cells of enteric neurons, play an important role in guiding and influencing its own innervation. Normal maturation was inhibited in neurons cultured with smooth muscle cells of aganglionic colon in comparison to normal colon. Furthermore, it was demonstrated that levels of neurotrophic factors, crucial in the development and survival of enteric neurons, are decreased in circular muscle layers of aganglionic colon in comparison to normoganglionic colon. The smooth muscle cells of the aganglionic colon may represent an unfavorable microenvironment for neuronal development compared with the normally innervated region. Recently, markedly increased immunoreactivity of major histocompatibility complex (MHC) class II antigens and ICAM-1 was demonstrated in aganglionic bowel, suggesting the immunological mechanisms may be involved in the etiology of HD. Genetic factors have been implicated in the etiology of this condition because HD is known to occur in families and in association with some chromosomal abnormalities. Recent expansion of molecular genetics identified multiple susceptibility genes of HD, including the RET gene, the glial cell line-derived neurotrophic factor gene, the endothelin-B receptor gene, and endothelin-3 gene. Of these, inactivating mutations of the RET gene are the most frequent, occurring in 50% of familial and 15% to 20% of sporadic cases of HD. To date, despite extensive research, the exact etiology of this condition remains poorly understood. The present report describes the authors' current understanding of and recent progress in the etiology of HD.

Genetic aspects of Hirschsprung's disease

Hirschsprung's disease (HD) is a relatively common cause of intestinal obstruction in the newborn, characterized by the absence of autonomic ganglion cells in the terminal bowel. Existence of familial cases indicates that genetic factors may be involved in the etiology of some cases of HD. Different inheritance patterns observed in subsets of HD families or kindreds, and the detection of different chromosome aberrations in some HD patients, suggest genetic heterogeneity of HD. Recent expansion of molecular genetics has identified multiple susceptibility genes of HD. These include the RET gene, the glial cell-derived neurotrophic factor gene, the endothelin-B receptor gene, and endothelin-3 gene. Furthermore, some other genes or genetic factors are speculated to be implicated in the development of HD, and it is believed that multiple factors play a role in disease development in some cases. Taken together, these data suggest and may explain the complexity of the etiology of HD. This review focuses on recent advances in our understanding of the genetic aspects of HD.

The RET proto-oncogene: a challenge to our understanding of disease pathogenesis

RET gene alterations as disease-causative mutations have been demonstrated in five different disease entities: Hirschsprung's disease (HD); papillary thyroid carcinoma; and three types of inherited cancer syndromes: multiple endocrine neoplasia (MEN) 2A, MEN 2B, and familial medullary thyroid carcinoma. RET is expressed during embryogenesis in a temporally and spatially regulated manner, and plays an important role in the normal development of a variety of cell lineages, particularly in the establishment of the enteric nervous system. RET mutations observed in patients with HD are scattered along the gene without any hot spots, and possess a loss-of-function effect. RET mutations are detected with a higher incidence among familial cases (50%) than sporadic cases (15%-20%), and are more closely associated with long-segment HD than short-segment disease. In contrast to HD mutations, missense mutations observed in MEN 2 syndromes occur at specific codons, and gene rearrangements are characteristic in papillary thyroid carcinoma. Both missense mutations and gene rearrangements act in a dominant fashion, and cause constitutive phosphorylation on the tyrosine of RET and highly enhance RET kinase activity, leading to transforming or oncogenic activity.

Hirschprung's disease

Current evidence on the pathogenesis of Hirschprung's disease, then, favours the 'abnormal microenvironment' hypothesis wherein the developing and migrating normal neural crest cells confront a segmentally abnormal and hostile microenvironment in the colon. This hypothesis would account both for the congenital absence of ganglion cells in the wall of colon and also for the range of enteric neuronal abnormalities encountered including neuronal dysplasia, hypoganglionosis, and zonal aganglionosis. The abnormal constitution of the mesenchymal and basement membrane extracellular matrix in the affected segment of colon is presumably genetically determined and further understanding of the pathogenesis of this disorder will emerge as molecular geneticists characterise the specific genes and gene products associated with Hirschprung's disease. Advances in this field should permit gene probes to be developed to facilitate prenatal and postnatal diagnosis.

Hirschsprung's disease: one surgeon's experience in one institution

The clinical experience of 137 patients treated by one pediatric surgeon at HanYang University Hospital over 12 years was analyzed. The sex ratio was 3.6:1 with male predominance. Neonatal Hirschsprung's disease (HD) occurred in 70 cases (51.1%). One hundred fourteen cases (83.2%) were short-segment and 23 cases (16.8%) were long-segment disease, of which 4 cases were total colon aganglionosis. Symptoms were abdominal distension, vomiting, constipation, and delayed passage of meconium. Family history was noted in 4 cases: 3 involved siblings and 1 involved relatives. All patients were male and had short-segment diseases. There were 3 pairs of monozygotic twins discordant for HD. Seventy-seven two-stage Duhamel operations were performed at the age of 121 +/- 41.3 days. Primary Duhamel operations were performed on 30 children. Anorectal myectomies were performed on 12 cases of short rectal aganglionosis. The incidence of enterocolitis was 25.5% preoperatively and 10.1% postoperatively. Complications after the Duhamel operation were intestinal obstruction (3), wound disruption (4), and septum reformation (3) with fecaloma formation in the blind rectal pouch. Bowel function was normalized within 3 months in 77.3% and within 1 year after operation in 91.6%. Duhamel operation with a GIA stapler after preliminary colostomy could be done at the age of 104 days on average with good functional results and with acceptable morbidity. Primary Duhamel operation could be done safely on the patients whose conditions were diagnosed after 90 days of life with good results. There was no mortality after Duhamel operation.

Familial Hirschsprung's disease: 20 cases in 12 kindreds

This report describes 20 infants and children with a family history of Hirschsprung's disease in 12 kindreds. A total of 260 patients were treated for Hirschsprung's disease (1972 to 1991), yielding a familial incidence of 8%. There were no families with consanguineous marriage. Sixteen patients were male and four were female. The mean age at diagnosis was 18 days. Clinical presentation included delayed passage of meconium in 15, abdominal distention in 11, vomiting in 9, feeding abnormalities in 3, and complete bowel obstruction in 1. Associated congenital anomalies occurred in 25% of the patients. The extent of aganglionosis was rectal in 4, sigmoid in 4, left colon in 2, transverse or right colon in 2, and total colonic in 8. Enterocolitis occurred in 7 patients (35%); 2 at diagnosis, 2 after an ostomy, and 3 after a pull-through procedure. There were no deaths associated with enterocolitis. All patients had a proximal diverting colostomy or ileostomy, and 19 of 20 underwent a definitive pull-through procedure. Three patients were lost to follow-up and one patient died of complications of multiple congenital anomalies unassociated with Hirschsprung's disease. Of the remaining 16 patients, all of whom have undergone a pull-through procedure, 11 are fully continent, 2 have nighttime soiling, 2 are too young to evaluate bowel function, and 1 still has an ostomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Hirschsprung's disease: clinical and experimental observations

Hirschsprung's disease (HD) is a relatively common cause of intestinal obstruction in the newborn. It is characterized by an absence of ganglion cells in the distal bowel beginning at the internal sphincter and extending proximally for varying distances. The etiology of HD-associated enterocolitis remains a complex issue. This study has provided further support for a possible infectious etiology of enterocolitis complicating HD.

Contemporary approaches toward understanding the pathogenesis of Hirschsprung disease

Hirschsprung disease (HD), or congenital aganglionosis coli, is a birth defect with heterogeneous causes. In an effort to understand the molecular and cellular bases for this disorder, researchers have investigated enteric neurodevelopment in normal animals and compared these findings with observations of inbred animal strains that develop aganglionosis coli due to mutations at specific genetic loci. Recent technological advances, including use of retroviral and fluorescent lineage makers, immunohistochemical probes, and transgenic mice, have provided insights into the origins, behavior, and properties of enteric neuroblasts. Experiments with mutant murine embryos indicate that aganglionosis coli results from primary failure of neural crest-derived neuroblasts to colonize the distal colon. In at least one model, impaired colonization by neuroblasts may be secondary to environmental defects restricted to colonic mesenchyme. The discovery that human piebald trait, a hereditary disorder with a high incidence of HD, is caused by mutations in a growth factor receptor highlights the importance of regulatory intercellular interactions between nonneuroblastic mesenchyme and neuroblasts during normal development of the enteric nervous system. These observations, coupled with advances in molecular genetics, set the stage for dramatic progress in this field of research in the near future.