Mowat-Wilson syndrome: Case report.

BACKGROUND: Mowat-Wilson syndrome (MWS) is a rare genetic condition resulting in multiple congenital anomalies, including facial dysmorphism, structural anomalies of the internal organs, functional disorders, and, although less commonly, ocular abnormalities. To present a child with MWS and eye abnormalities. METHODS: A 3-year-old boy was born at 37 weeks of pregnancy with dysmorphic features, neurodevelopmental disorders, genetically confirmed MWS, nystagmus, strabismus, and suspicion of congenital glaucoma. Ophthalmic examination was carried out under general anesthesia; eyeball ultrasound and electrophysiological examination (flash visual evoked potentials) were also performed. RESULTS: The examinations revealed nystagmus, a normal response of pupils to light in both eyes, and normal intraocular pressure, that is, 17 and 18 mm Hg in the right and left eye, respectively. Corneal thickness was 606 µm in the right eye and 588 µm in the left eye. Gonioscopy revealed displacement of Schwalbe line anterior to the limbus of the cornea (posterior embryotoxon). Fundus examination revealed a pink optic disk with a cup-to-disc ratio of 0.5, macular pigment regrouping, and normal blood vessels. Flash visual evoked potentials: P2 latency was normal. P2 amplitude from the left hemisphere was reduced to 50%, and P2 amplitude over the right hemisphere was normal. CONCLUSION: Children with genetically determined congenital anomalies need regular ophthalmic checkups to accurately assess the eye and determine the prospects of vision function development.

A multi-center cross-sectional comparison of parent-reported quality of life and bowel function between anorectal malformation and Hirschsprung's disease patients with versus those without Down syndrome.

PURPOSE: Down syndrome (DS) is a common abnormality associated with anorectal malformation (ARM) and Hirschsprung's disease (HD). However, quality of life (QOL) in ARM and HD patients with DS is under-researched. This study compares parent-reported QOL and bowel function in ARM and HD patients with DS to those without. METHODS: Between December 2020 to February 2023, parents of ARM and HD patients with and without DS aged 3-17 years who had undergone surgery > 12 months prior at four tertiary referral centers were recruited. We used the Pediatric Quality of Life Inventory™ (PedsQL™) Generic Core Scales, General Well-Being (GWB) Scale and Family Impact (FI) Module questionnaires, and the Rintala bowel function score (BFS). RESULTS: There were 101 ARM, 9 (8.9%) of whom had DS; and 87 HD, of whom 6 (6.9%) had DS. Parent-reported Core scores in ARM and HD with DS were comparable to those without DS. However, ARM and HD with DS had worse scores in the FI Module and bowel function than those without DS. CONCLUSION: Although parent-reported QOL in ARM and HD with DS is similar to those without DS, family impact and BFS are worse. Our findings are limited by small sample size in proportion of DS patients.

Faecal incontinence: Retentive, non-retentive and when to suspect organic pathology.

BACKGROUND: Faecal incontinence is a highly prevalent and very distressing condition that occurs throughout the entire paediatric age. AIM: To summarise advances in the understanding of the epidemiology, pathophysiology, evaluation and treatment of children with faecal incontinence due to either disorders of gut-brain interaction or organic diseases. METHODS: Literature review on prevalence, impact, diagnosis and treatment options for children with faecal incontinence, interspersed with observations from the author's lifelong career focused on evaluation of children with motility disorders. RESULTS: Faecal incontinence in children is most commonly due to unrecognised or insufficiently treated functional constipation with overflow incontinence. Non-retentive faecal incontinence (NRFI) is probably more common than previously thought and is particularly challenging to treat. Organic diseases such as anorectal malformations (ARMs), Hirschsprung disease and spinal defects are often associated with faecal incontinence; in these conditions, faecal incontinence has a profound impact on quality of life. Recognition of the different pathophysiologic mechanisms causing the incontinence is essential for a successful treatment plan. A thorough physical examination and history is all that is needed in the diagnosis of the causes of faecal incontinence related to disorders of gut-brain interaction. Colonic transit studies or x-rays may help to differentiate retentive from NRFI. Manometry tests are helpful in determining the mechanisms underlying the incontinence in children operated on for ARMs or Hirschsprung diseases. Multiple behavioural, medical and surgical interventions are available to lessen the severity of faecal incontinence and its impact on the daily life of affected individuals. CONCLUSIONS: Recent advances offer hope for children with faecal incontinence.

Anorectal malformation and Hirschsprung's disease: a cross-sectional multicentre comparison of quality of life and bowel function to a healthy population.

PURPOSE: Children with anorectal malformation (ARM) and Hirschsprung's disease (HD) often experience bowel symptoms into adulthood, despite definitive surgery. This study evaluates the quality of life (QOL) and bowel functional outcome of children treated for ARM and HD in comparison to healthy controls. METHODS: Between December 2020 and February 2023, we recruited patients with ARM and HD aged 3-17 years at four tertiary referral centres, who had primary corrective surgery done >12 months prior. Healthy controls were age-matched and sex-matched. All participants completed the Pediatric Quality of Life Inventory Generic Core Scales 4.0, General Well-Being (GWB) Scale 3.0 and Family Impact (FI) Module 2.0 Questionnaires. Bowel Function Score (BFS) Questionnaires were also administered. We also performed subgroup analysis according to age categories. Appropriate statistical analysis was performed with p<0.05 significance. Ethical approval was obtained. RESULTS: There were 306 participants: 101 ARM, 87 HD, 118 controls. Patients with ARM and HD had significantly worse Core and FI Scores compared with controls overall and in all age categories. In the GWB Scale, only ARM and HD adolescents (13-17 years) had worse scores than controls. ARM and HD had significantly worse BFSs compared with controls overall and in all age categories. There was significant positive correlation between BFS and Core Scores, GWB Scores and FI Scores. CONCLUSION: Patients with ARM and HD had worse QOL than controls. Lower GWB Scores in adolescents suggests targeted interventions are necessary. Bowel function influences QOL, indicating the need for continuous support into adulthood.

Utility of colonic manometry in children with Hirschsprung disease.

OBJECTIVES: Abnormal motility of the residual colon has been reported in post-pull-through Hirschsprung disease (PT-HSCR) patients with persistent defecation problems. We reviewed the role of colonic manometry (CM) in the management of defecation disorders in these patients. METHODS: We retrospectively reviewed the medical record of PT-HSCR children who underwent CM for persistent symptoms of abnormal defecation. We reviewed their clinical course and its relation to CM findings. RESULTS: Thirty PT-HSCR patients underwent CM, of which five were diagnosed with transition zone pull-through and were excluded. Of the remaining 25 patients, 16 had colonic dysmotility, 8 had normal CM, and one had colonic hypermotility. In patients with dysmotility, five responded to ongoing medical management, three required surgical intervention (ileostomy), three remained symptomatic with medical management but not yet received surgical intervention, and five were lost to follow-up. In patients with normal CM, four responded to ongoing medical therapy, two required additional surgery (antegrade enema procedure), and two were lost to follow-up. The patient with hypermotility improved with adding loperamide. CONCLUSIONS: Colonic dysmotility can occur in PT-HSCR patients with persistent defecation problems. CM was helpful in delineating the degree of colonic neuromuscular dysfunction. CM results were used in conjunction with other clinical data to determine optimal management. Our findings support that medical management should first be optimized before consideration of colonic manometry and surgical interventions.

Enteric Nervous System Striped Patterning and Disease: Unexplored Pathophysiology.

The enteric nervous system (ENS) controls gastrointestinal (GI) motility, and defects in ENS development underlie pediatric GI motility disorders. In disorders such as Hirschsprung's disease (HSCR), pediatric intestinal pseudo-obstruction (PIPO), and intestinal neuronal dysplasia type B (INDB), ENS structure is altered with noted decreased neuronal density in HSCR and reports of increased neuronal density in PIPO and INDB. The developmental origin of these structural deficits is not fully understood. Here, we review the current understanding of ENS development and pediatric GI motility disorders incorporating new data on ENS structure. In particular, emerging evidence demonstrates that enteric neurons are patterned into circumferential stripes along the longitudinal axis of the intestine during mouse and human development. This novel understanding of ENS structure proposes new questions about the pathophysiology of pediatric GI motility disorders. If the ENS is organized into stripes, could the observed changes in enteric neuron density in HSCR, PIPO, and INDB represent differences in the distribution of enteric neuronal stripes? We review mechanisms of striped patterning from other biological systems and propose how defects in striped ENS patterning could explain structural deficits observed in pediatric GI motility disorders.

Sexual function and fertility of adult males with anorectal malformations or Hirschsprung disease.

PURPOSE: The long-term impact of anorectal malformations (ARM) and Hirschsprung disease (HD) on sexual function is well recognized but understudied. This study evaluated self-reported sexual and fertility outcomes in adult males with ARM and HD. METHODS: This was an IRB approved, prospective study of males in the Adult Colorectal Research Registry who completed surveys between October 2019 and March 2022. Electronic surveys were administered after consenting to being contacted for research. Patients completed the International Index of Erectile Function (IIEF) questionnaire and provided information on fertility outcomes. RESULTS: Sixty-five patients completed outcome questionnaires: 11 (16.9%) had HD and 54 (83.1%) had an ARM. Nineteen patients reported some degree of erectile dysfunction per IIEF criteria, a greater proportion of whom have ARM (p = 0.046). Twenty (30.7%) have reported having children; there were no differences in rates between HD and ARM patients. Most patients had not attempted to conceive, but eight patients, all of whom have ARM, have pursued fertility investigation or treatments. CONCLUSION: More patients with ARM reported some degree of erectile dysfunction compared to those with HD. Additionally, some have required fertility treatments. Further investigation is warranted to ensure true low rates of sexual and fertility dysfunction in patients with HD.

Optimal timing of definitive surgery for Hirschsprung's disease to achieve better long-term bowel function.

PURPOSE: Few studies have focused on the operative age for Hirschsprung's disease (HD). We evaluated the optimal timing of surgery in HD patients based on their long-term bowel function. METHODS: HD was diagnosed in 65 pediatric patients in our institute between 1992 and 2018. Twenty-five patients underwent the Soave-Denda procedure (SD) and 40 underwent transanal endorectal pull-through (TA). We divided these patients into two groups: those who underwent surgery at < 6 months of age (younger group) and those who underwent surgery at 6-12 months of age (older group). We assessed bowel function at 5, 7, and 9 years of age. RESULTS: The bowel function of the patients who underwent the SD did not differ significantly between the groups. Similarly, the total bowel-function scores of the patients who underwent TA did not differ between the groups at any age. However, the soiling score at 7 years of age in the older group of patients who underwent TA was significantly lower than that in the younger group (p = 0.02). CONCLUSIONS: Our data suggest that to achieve optimal bowel function, TA should be performed at < 6 months of age.

Structural heart defects associated with ETB mutation, a cause of Hirschsprung disease.

BACKGROUND: HSCR, a colonic neurocristopathy affecting 1/5000 births, is suggested to associate with cardiac septal defects and conotruncal malformations. However, we question subtle cardiac changes maybe more commonly present due to multi-regulations by HSCR candidate genes, in this instance, ETB. To investigate, we compared the cardiac morphology and quantitative measurements of sl/sl rat to those of the control group. METHODS: Eleven neonatal rats were generated from heterozygote (ETB+/-) crossbreeding. Age and bodyweight were recorded at time of sacrifice. Diffusion-staining protocols with 1.5% iodine solution was completed prior to micro-CT scanning. All rats were scanned using an in vivo micro-CT scanner, Caliper Quantum FX, followed by two quality-control scans using a custom-built ex vivo micro-CT system. All scans were reviewed for gross cardiac dysmorphology. Micro-CT data were segmented semi-automatically post-NLM filtering for: whole-heart, LV, RV, LA, RA, and aortic arch. Measurements were taken with Drishti. Following image analysis, PCR genotyping of rats was performed: five sl/sl rats, three wildtype, and three heterozygotes. Statistical comparisons on organ volume, growth rate, and organ volume/bodyweight ratios were made between sl/sl and the control group. RESULTS: Cardiac morphology and constituents were preserved. However, significant volumetric reductions were recorded in sl/sl rats with respect to the control: whole heart (38.70%, p value = 0.02); LV (41.22%, p value = 0.01), RV (46.15%, p value = 0.02), LA (44.93%, p value = 0.06), and RA (39.49%, p value = 0.02). Consistent trend was observed in growth rate (~ 20%) and organ-volume/bodyweight ratios (~ 25%). On the contrary, measurements on aortic arch demonstrated no significant difference among the two groups. CONCLUSION: Despite the presence of normal morphology, significant cardiac growth retardation was detected in sl/sl rat, supporting the likely association of cardiac anomalies with HSCR, at least in ETB-/- subtype. Structural reduction was likely due to a combination of failure to thrive from enteric dysfunction, alterations to CaNCC colonization, and importantly coronary hypoperfusion from elevated ET-1/ETA-mediated hypervasoconstriction. Little correlation was detected between aortic arch development and sl/sl rat, supporting minor ETB role in large vessels. Although further clinical study is warranted, HSCR patients may likely require cardiac assessment in view of potential congenital cardiac defects.

Interstitial cells of Cajal and human colon motility in health and disease.

Our understanding of human colonic motility, and autonomic reflexes that generate motor patterns, has increased markedly through high-resolution manometry. Details of the motor patterns are emerging related to frequency and propagation characteristics that allow linkage to interstitial cells of Cajal (ICC) networks. In studies on colonic motor dysfunction requiring surgery, ICC are almost always abnormal or significantly reduced. However, there are still gaps in our knowledge about the role of ICC in the control of colonic motility and there is little understanding of a mechanistic link between ICC abnormalities and colonic motor dysfunction. This review will outline the various ICC networks in the human colon and their proven and likely associations with the enteric and extrinsic autonomic nervous systems. Based on our extensive knowledge of the role of ICC in the control of gastrointestinal motility of animal models and the human stomach and small intestine, we propose how ICC networks are underlying the motor patterns of the human colon. The role of ICC will be reviewed in the autonomic neural reflexes that evoke essential motor patterns for transit and defecation. Mechanisms underlying ICC injury, maintenance, and repair will be discussed. Hypotheses are formulated as to how ICC dysfunction can lead to motor abnormalities in slow transit constipation, chronic idiopathic pseudo-obstruction, Hirschsprung's disease, fecal incontinence, diverticular disease, and inflammatory conditions. Recent studies on ICC repair after injury hold promise for future therapies.

Clinical predictors of readmission after surgery for Hirschsprung disease.

ABSTRACT: The reasons for readmission of children with Hirschsprung disease (HD) are multiple. The study aims to predict the relevant factors for the readmission of children with HD by collecting and analyzing the relevant data of the child's admission to the hospital at the time of surgery.A retrospective review was performed including all patients with surgical treatment of HD at our institution between the years of 2011 to 2020. Univariate and multivariate Logistic regression analysis were performed to obtain the independent risk factor for this study. The receiver operating characteristic curve (ROC) were used to assess the performance of derived models.A total of 162 patients were identified. The average presurgery weights were 6.93 ±â€Š1.78 kg in the readmission group and 8.38 ±â€Š3.17 kg in the non-readmission group. Six children were classified as a low-weight in the readmission group, and 11 children classified as low-weight in the non-readmission group. The length of the intestinal tube after resection was 25.25 ±â€Š15.21 cm in the readmission group, and 16.23 ±â€Š4.10 cm in the non-readmission group. The ROC for the prediction model of readmission after HD surgery (AUC = 0.811).In children undergoing the HD surgery, we showed preoperative low body weight and long intra-operative bowel resection significantly increase the probability of readmission due to complications.

Genome-wide analysis of DNA methylation in Hirschsprung enteric precursor cells: unraveling the epigenetic landscape of enteric nervous system development.

BACKGROUND: Hirschsprung disease (HSCR, OMIM 142623) is a rare congenital disorder that results from a failure to fully colonize the gut by enteric precursor cells (EPCs) derived from the neural crest. Such incomplete gut colonization is due to alterations in EPCs proliferation, survival, migration and/or differentiation during enteric nervous system (ENS) development. This complex process is regulated by a network of signaling pathways that is orchestrated by genetic and epigenetic factors, and therefore alterations at these levels can lead to the onset of neurocristopathies such as HSCR. The goal of this study is to broaden our knowledge of the role of epigenetic mechanisms in the disease context, specifically in DNA methylation. Therefore, with this aim, a Whole-Genome Bisulfite Sequencing assay has been performed using EPCs from HSCR patients and human controls. RESULTS: This is the first study to present a whole genome DNA methylation profile in HSCR and reveal a decrease of global DNA methylation in CpG context in HSCR patients compared with controls, which correlates with a greater hypomethylation of the differentially methylated regions (DMRs) identified. These results agree with the de novo Methyltransferase 3b downregulation in EPCs from HSCR patients compared to controls, and with the decrease in the global DNA methylation level previously described by our group. Through the comparative analysis of DMRs between HSCR patients and controls, a set of new genes has been identified as potential susceptibility genes for HSCR at an epigenetic level. Moreover, previous differentially methylated genes related to HSCR have been found, which validates our approach. CONCLUSIONS: This study highlights the relevance of an adequate methylation pattern for a proper ENS development. This is a research area that provides a novel approach to deepen our understanding of the etiopathogenesis of HSCR.

Disorders of the enteric nervous system - a holistic view.

The enteric nervous system (ENS) is the largest division of the peripheral nervous system and closely resembles components and functions of the central nervous system. Although the central role of the ENS in congenital enteric neuropathic disorders, including Hirschsprung disease and inflammatory and functional bowel diseases, is well acknowledged, its role in systemic diseases is less understood. Evidence of a disordered ENS has accumulated in neurodegenerative diseases ranging from amyotrophic lateral sclerosis, Alzheimer disease and multiple sclerosis to Parkinson disease as well as neurodevelopmental disorders such as autism. The ENS is a key modulator of gut barrier function and a regulator of enteric homeostasis. A 'leaky gut' represents the gateway for bacterial and toxin translocation that might initiate downstream processes. Data indicate that changes in the gut microbiome acting in concert with the individual genetic background can modify the ENS, central nervous system and the immune system, impair barrier function, and contribute to various disorders such as irritable bowel syndrome, inflammatory bowel disease or neurodegeneration. Here, we summarize the current knowledge on the role of the ENS in gastrointestinal and systemic diseases, highlighting its interaction with various key players involved in shaping the phenotypes. Finally, current flaws and pitfalls related to ENS research in addition to future perspectives are also addressed.

[Recommendations for the diagnosis and treatment of persistent postsurgical symptoms in Hirschsprung disease]. / Recomendaciones para el diagnóstico y el tratamiento de los síntomas posquirúrgicos persistentes en la enfermedad de Hirschsprung.

Hirschsprung disease is characterized by the lack of migration of intrinsic parasympathetic ganglia from neural crest and consequently absence of them at varying length of the bowel, resulting in functional obstruction. The incidence is 1 per 5000 births. After surgery, short term and long term comorbidity commonly occurs. The aim of this article is to revise the main causes of ongoing symptoms after surgery in Hirschsprung disease patients and to show a diagnostic and therapeutic algorithm that can be developed in our community.

La enfermedad de Hirschsprung ocurre en 1 de cada 5000 nacimientos. La falla de migración de las células ganglionares desde la cresta neural en dirección cefalocaudal genera su ausencia en parte o todo el colon. Se manifiesta con falta de eliminación de meconio, distensión abdominal y dificultades en la evacuación. Luego del tratamiento quirúrgico, existen complicaciones a corto y largo plazo. El objetivo de esta publicación es describir las principales causas de síntomas persistentes en los pacientes operados por enfermedad de Hirschsprung y presentar un algoritmo diagnóstico-terapéutico factible de ser realizado en nuestro medio.

Mowat Wilson syndrome and Hirschsprung disease: a retrospective study on functional outcomes.

AIM OF THE STUDY: Mowat Wilson syndrome (MWS) is a complex genetic disorder due to mutation or deletion of the ZEB2 gene (ZFHX1B), including multiple clinical features. Hirschsprung disease is associated with this syndrome with a prevalence between 43 and 57%. The aim of this study was to demonstrate the severe outcomes and the high complication rates in children with MWS, focusing on their complicated follow-up. METHODS: A retrospective comparative study was conducted on patients referred to Robert-Debré Children's Hospital for MWS from 2003 to 2018. Multidisciplinary follow-up was carried out by surgeons, geneticists, gastroenterologists, and neurologists. Data regarding patient characteristics, surgical management, postoperative complications, and functional outcomes were collected. RESULTS: Over this period of 15 years, 23 patients were diagnosed with MWS. Hirschsprung disease was associated with 10 of them (43%). Of these cases, two patients had recto-sigmoïd aganglionosis (20%), three had aganglionic segment extension to the left colic angle (30%), two to the right colic angle (20%), and three to the whole colon (30%). The median follow-up was 8.5 years (2 months-15 years). All patients had seizures and intellectual disability. Six children (60%) presented with cardiac defects. At the last follow-up, three patients still had a stoma diversion and 7 (70%) were fed orally. One patient died during the first months. Eight (80%) of these children required a second surgery due to complications. At the last follow-up, three patients reported episodes of abdominal bloating (42%), one recurrent treated constipation (14.3%), and one soiling (14.3%). Genetic analysis identified three patients with heterozygous deletions, three with codon mutations, and three with frameshift mutations. CONCLUSIONS: MWS associated with Hirschsprung disease has a high rate of immediate surgical complications but some patients may achieve bowel function comparable with non-syndromic HD patients. A multidisciplinary follow-up is required for these patients. LEVEL OF EVIDENCE: Retrospective observational single cohort study, Level 3.

Glial Cell-Derived Neurotrophic Factor Induces Enteric Neurogenesis and Improves Colon Structure and Function in Mouse Models of Hirschsprung Disease.

BACKGROUND & AIMS: Hirschsprung disease (HSCR) is a life-threatening birth defect in which the distal colon is devoid of enteric neural ganglia. HSCR is treated by surgical removal of aganglionic bowel, but many children continue to have severe problems after surgery. We studied whether administration of glial cell derived neurotrophic factor (GDNF) induces enteric nervous system regeneration in mouse models of HSCR. METHODS: We performed studies with four mouse models of HSCR: Holstein (HolTg/Tg, a model for trisomy 21-associated HSCR), TashT (TashTTg/Tg, a model for male-biased HSCR), Piebald-lethal (Ednrbs-l//s-l, a model for EDNRB mutation-associated HSCR), and Ret9/- (with aganglionosis induced by mycophenolate). Mice were given rectal enemas containing GDNF or saline (control) from postnatal days 4 through 8. We measured survival times of mice, and colon tissues were analyzed by histology, immunofluorescence, and immunoblots. Neural ganglia regeneration and structure, bowel motility, epithelial permeability, muscle thickness, and neutrophil infiltration were studied in colon tissues and in mice. Stool samples were collected, and microbiomes were analyzed by 16S rRNA gene sequencing. Time-lapse imaging and genetic cell-lineage tracing were used to identify a source of GDNF-targeted neural progenitors. Human aganglionic colon explants from children with HSCR were cultured with GDNF and evaluated for neurogenesis. RESULTS: GDNF significantly prolonged mean survival times of HolTg/Tg mice, Ednrbs-l//s-l mice, and male TashTTg/Tg mice, compared with control mice, but not Ret9/- mice (which had mycophenolate toxicity). Mice given GDNF developed neurons and glia in distal bowel tissues that were aganglionic in control mice, had a significant increase in colon motility, and had significant decreases in epithelial permeability, muscle thickness, and neutrophil density. We observed dysbiosis in fecal samples from HolTg/Tg mice compared with feces from wild-type mice; fecal microbiomes of mice given GDNF were similar to those of wild-type mice except for Bacteroides. Exogenous luminal GDNF penetrated aganglionic colon epithelium of HolTg/Tg mice, inducing production of endogenous GDNF, and new enteric neurons and glia appeared to arise from Schwann cells within extrinsic nerves. GDNF application to cultured explants of human aganglionic bowel induced proliferation of Schwann cells and formation of new neurons. CONCLUSIONS: GDNF prolonged survival, induced enteric neurogenesis, and improved colon structure and function in 3 mouse models of HSCR. Application of GDNF to cultured explants of aganglionic bowel from children with HSCR induced proliferation of Schwann cells and formation of new neurons. GDNF might be developed for treatment of HSCR.

Immunodeficiency in cartilage-hair hypoplasia: Pathogenesis, clinical course and management.

Cartilage-hair hypoplasia (CHH) is an autosomal recessive syndromic immunodeficiency with skeletal dysplasia, short stature, hypotrichosis, variable degree of immune dysfunction and increased incidence of anaemia, Hirschsprung disease and malignancy. CHH is caused by variants in the RMRP gene, encoding the untranslated RNA molecule of the mitochondrial RNA-processing endoribonuclease, which participates in for example cell cycle regulation and telomere maintenance. Recent studies have expanded our understanding of the complex pathogenesis of CHH. Immune dysfunction has a major impact on clinical course and prognosis. Clinical features of immune dysfunction are highly variable, progressive and include infections, lung disease, immune dysregulation and malignancy. Mortality is increased compared with the general population, due to infections, malignancy and pulmonary disease. Several risk factors for early mortality have been reported in the Finnish CHH cohort and can be used to guide management. Newborn screening for severe combined immunodeficiency can possibly be of prognostic value in CHH. Regular follow-up by a multidisciplinary team should be implemented to address immune dysfunction in all patients with CHH, also in asymptomatic cases. Haematopoietic stem cell transplantation can cure immune dysfunction, but its benefits in mildly symptomatic patients with CHH remain debatable. Further research is needed to understand the mechanisms behind the variability of clinical features, to search for potential molecular treatment targets, to examine and validate risk factors for early mortality outside the Finnish CHH cohort and to develop management guidelines. This review focuses on the pathogenesis, clinical course and management of CHH.

37/67-laminin receptor facilitates neural crest cell migration during enteric nervous system development.

Enteric nervous system (ENS) development is governed by interactions between neural crest cells (NCC) and the extracellular matrix (ECM). Hirschsprung disease (HSCR) results from incomplete NCC migration and failure to form an appropriate ENS. Prior studies implicate abnormal ECM in NCC migration failure. We performed a comparative microarray of the embryonic distal hindgut of wild-type and EdnrBNCC-/- mice that model HSCR and identified laminin-ß1 as upregulated in EdnrBNCC-/- colon. We identified decreased expression of 37/67 kDa laminin receptor (LAMR), which binds laminin-ß1, in human HSCR myenteric plexus and EdnrBNCC-/- NCC. Using a combination of in vitro gut slice cultures and ex vivo organ cultures, we determined the mechanistic role of LAMR in NCC migration. We found that enteric NCC express LAMR, which is downregulated in human and murine HSCR. Binding of LAMR by the laminin-ß1 analog YIGSR promotes NCC migration. Silencing of LAMR abrogated these effects. Finally, applying YIGSR to E13.5 EdnrBNCC-/- colon explants resulted in 80%-100% colonization of the hindgut. This study adds LAMR to the large list of receptors through which NCC interact with their environment during ENS development. These results should be used to inform ongoing integrative, regenerative medicine approaches to HSCR.