Genome-wide analysis identifies MYH11 compound heterozygous variants leading to visceral myopathy corresponding to late-onset form of megacystis-microcolon-intestinal hypoperistalsis syndrome.

Megacystis-microcolon-hypoperistalsis-syndrome (MMIHS) is a rare and early-onset congenital disease characterized by massive abdominal distension due to a large non-obstructive bladder, a microcolon and decreased or absent intestinal peristalsis. While in most cases inheritance is autosomal dominant and associated with heterozygous variant in ACTG2 gene, an autosomal recessive transmission has also been described including pathogenic bialellic loss-of-function variants in MYH11. We report here a novel family with visceral myopathy related to MYH11 gene, confirmed by whole genome sequencing (WGS). WGS was performed in two siblings with unusual presentation of MMIHS and their two healthy parents. The 38 years-old brother had severe bladder dysfunction and intestinal obstruction, whereas the 30 years-old sister suffered from end-stage kidney disease with neurogenic bladder and recurrent sigmoid volvulus. WGS was completed by retrospective digestive pathological analyses. Compound heterozygous variants of MYH11 gene were identified, associating a deletion of 1.2 Mb encompassing MYH11 inherited from the father and an in-frame variant c.2578_2580del, p.Glu860del inherited from the mother. Pathology analyses of the colon and the rectum revealed structural changes which significance of which is discussed. Cardiac and vascular assessment of the mother was normal. This is the second report of a visceral myopathy corresponding to late-onset form of MMIHS related to compound heterozygosity in MYH11; with complete gene deletion and a hypomorphic allele in trans. The hypomorphic allele harbored by the mother raised the question of the risk of aortic disease in adults. This case shows the interest of WGS in deciphering complex phenotypes, allowing adapted diagnosis and genetic counselling.

A new spectrum of neonatal urethral pathologies in the era of early vesicoamniotic shunting?

PURPOSE: Intrauterine vesicoamniotic shunting (VAS) was shown to affect survival of male fetuses with megacystis in suspected lower urinary tract obstruction (LUTO). Data on postnatal management are largely lacking. We aim to describe the pathologies diagnosed in children born after vesicoamniotic shunt placement in early pregnancy for megacystis. METHODS: All newborns with previous intrauterine VAS treated in our institution were analyzed retrospectively. We evaluated the clinical spectrum of urethral pathologies. We also compared patients who received a shunt before the 17th gestational week with those who received it later. RESULTS: Between 2014 and 2023, 26 patients (all male) with a history of VAS for suspected LUTO were treated in our institution postnatally. Five fetuses with dislocated shunts underwent re-implantation in utero. Overall, premature birth before the 38th week of gestation was observed in 14 patients. Seven patients received a Harrison® shunt whereas 19 received a Somatex® shunt. Twelve patients required surgical shunt removal under general anesthesia due to shunt migration/embedding. Posterior urethral valves were found in 10/26 patients, 10/26 patients showed a urethral hypoplasia [Fig. 1] and two patients had urethral duplications. In two patients, we identified a prune belly syndrome. One patient had posterior and anterior urethral valves. One patient had a high grade bilateral vesicoureteral reflux without LUTO. The 11 patients shunted early (before 17GW) showed a trend towards a higher proportion of urethral hypoplasia in the early shunt group (54% vs. 26%) without statistical significance. CONCLUSION: In our observation, patients treated with VAS had a noticeable high proportion of complex urethral pathologies such as urethral hypoplasia. These data should be taken into consideration for prenatal counselling of parents and planning of postnatal management.

Bladder duplication in the male cat: the first case report in China.

BACKGROUND: Bladder duplication is a rare congenital lower urinary tract anomaly disease characterized by the presence of two bladders, possibly with duplication of the urethra. This disease is rarely reported in cats. The clinical symptoms are commonly occult, with increased difficulty in making a definitive diagnosis, especially if there is no obvious urethral duplication. The diagnosis is typically based on radiographs and ultrasound, with computer tomography serving as a more advanced imaging diagnostic modality. Cases of duplicated bladders with accessory tubular tissues are even scarcer in both human and veterinary medicine. CASE PRESENTATION: A 6-year-old male neutered cat was brought to the hospital because of vomiting and constipation. Cystography revealed increased soft tissue density of a fusiform structure in the lower middle abdomen. The purulent-filled cavitary structure and the accessory tubular structure were removed via surgery, and histopathological examination confirmed a double bladder with attached accessory tubular tissue. After antibiotic treatment, the cat recovered uneventfully. CONCLUSION: This is the first case of bladder duplication in China and the first case of feline bladder duplication with tubular structure attachment in the world. This information will provide a reference for the diagnosis and treatment of similar cases in the future.

The utility of gene sequencing in identifying an underlying genetic disorder in prenatally suspected lower urinary tract obstruction.

OBJECTIVE: Fetal megacystis generally presents as suspected lower urinary tract obstruction (LUTO), which is associated with severe perinatal morbidity. Genetic etiologies underlying LUTO or a LUTO-like initial presentation are poorly understood. Our objectives are to describe single gene etiologies in fetuses initially ascertained to have suspected LUTO and to elucidate genotype-phenotype correlations. METHODS: A retrospective case series of suspected fetal LUTO positive for a molecular diagnosis was collected from five centers in the Fetal Sequencing Consortium. Demographics, sonograms, genetic testing including variant classification, and delivery outcomes were abstracted. RESULTS: Seven cases of initially prenatally suspected LUTO-positive for a molecular diagnosis were identified. In no case was the final diagnosis established as urethral obstruction that is, LUTO. All variants were classified as likely pathogenic or pathogenic. Smooth muscle deficiencies involving the bladder wall and interfering with bladder emptying were identified in five cases: MYOCD (2), ACTG2 (2), and MYH11 (1). Other genitourinary and/or non-genitourinary malformations were seen in two cases involving KMT2D (1) and BBS10 (1). CONCLUSION: Our series illustrates the value of molecular diagnostics in the workup of fetuses who present with prenatally suspected LUTO but who may have a non-LUTO explanation for their prenatal ultrasound findings.

Sagittal septum duplication of bladder and duplication of posterior urethra combined with congenital megacolon: a case report and literature review.

BACKGROUND: Duplication of the bladder with duplication of the posterior urethra is a relatively rare congenital malformation. Cases of sagittal septum duplication of the bladder with duplication of the posterior urethra have rarely been reported. Furthermore, the combination thereof with congenital megacolon is rare. CASE PRESENTATION: A 21-year-old male was admitted to our hospital because of frequent urination for two months. He presented to another hospital first with frequent urination and underwent computed tomography (CT) and testicular biopsy. Anti-inflammatory therapy was administered by the doctor to the patient. For further diagnosis and treatment, the patient went to the outpatient department in our hospital on June 6, 2022. After admission, the patient underwent ultrasound, CT, MRI, cystoscopy, and other related examinations and tests. The examination results suggested that the patient had duplication of the bladder with duplication of the posterior urethra. In addition, the patient's mother reported that he had suffered from long-term constipation with abdominal distension before the age of 5 years. At the time, he was admitted to the local hospital and was diagnosed with congenital megacolon based on the relevant examinations. After the patient was diagnosed with duplication of bladder and urethra, the doctor recommended surgical treatment to the patient. However, he considered that he only had frequent urination symptoms, and chose conservative treatment rather than to undergo surgical treatment. Thus, the doctor prescribed anti-inflammatory treatment. Four months later, the patient reported that frequent urination symptoms persisted, and was also considering fertility-related problems. The outpatient follow-up will be continued. CONCLUSIONS: In this article, we summarize the imaging findings of duplication of the bladder with duplication of the posterior urethra and propose the advantages and disadvantages of each type of imaging examination. We also review the relevant literature on cases of bladders with duplication of the posterior urethra. The related differential diagnosis is summarized, and the significance of guiding clinical treatment and diagnosis is discussed.

Spontaneous rupture of bladder diverticulum with pseudo renal failure:A case report and literature review.

BACKGROUND: Spontaneous or non-traumatic bladder rupture is rare but can be life-threatening. Bladder rupture caused by a diverticulum is extremely rare, with only a few case reports in medical literature. CASE PRESENTATION: We report the case of a 32-year-old woman admitted to hospital complaints of abdominal pain, oliguria and ascites with no history of trauma. Laboratory tests revealed an elevated serum urea nitrogen(UN) level of 33.5 mmol/l and an elevated creatinine levels of 528 umol/l. X-ray cystography confirmed the rupture of a bladder diverticulum. Subsequent transurethral catheterization led to a prompt increase in urinary output, and serum creatinine level returned to 40 umol/l within 48 h. The patient was successfully treated with laparoscopic diverticulectomy. CONCLUSION: Clinicians should maintain a high level of suspicion for urinary bladder rupture in cases presenting with acute lower abdominal pain, urinary difficulties, and oliguria. When acute renal failure, complicated ascites, and an elevated peritoneal fluid creatinine or potassium level exceeding serum levels are observed, intraperitoneal urine leakage should be suspected without delay. This case emphasizes the importance of early diagnosis and intervention in managing this rare but serious condition.

A lmod1a mutation causes megacystis microcolon intestinal hypoperistalsis in a CRISPR/Cas9-modified zebrafish model.

PURPOSE: Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is defined as a congenital visceral myopathy with genetic mutations. However, the etiology and pathophysiology are not fully understood. We aimed to generate a gene leiomodin-1a (lmod1a) modification technique to establish a zebrafish model of MMIHS. METHODS: We targeted lmod1a in zebrafish using CRISPR/Cas9. After confirming the genotype, we measured the expression levels of the target gene and protein associated with MMIHS. A gut transit assay and spatiotemporal mapping were conducted to analyze the intestinal function. RESULTS: Genetic confirmation showed a 5-base-pair deletion in exon 1 of lmod1a, which caused a premature stop codon. We observed significant mRNA downregulation of lmod1a, myh11, myod1, and acta2 and the protein expression of Lmod1 and Acta2 in the mutant group. A functional analysis of the lmod1a mutant zebrafish showed that its intestinal peristalsis was fewer, slower, and shorter in comparison to the wild type. CONCLUSION: This study showed that targeted deletion of lmod1a in zebrafish resulted in depletion of MMIHS-related genes and proteins, resulting in intestinal hypoperistalsis. This model may have the potential to be utilized in future therapeutic approaches, such as drug discovery screening and gene repair therapy for MMIHS.

Megacystis-microcolon-intestinal hypoperistalsis syndrome: don't forget the bladder.

PURPOSE: Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a well described clinical condition, but reports are focused on microcolon and intestinal hypoperistalsis, while data on bladder management are scant. Aim of the study is to present urological concerns in MMIHS. METHODS: Retrospective evaluation of clinical data on urological management of MMIHS patients treated in the last 10 years. RESULTS: Six patients were enrolled (3 male, 3 female). Three girls had prenatal diagnosis of megacystis (1 vesicoamniotic shunt was placed). All patients had genetic diagnosis: 5 had ACTG2 gene mutations and 1 MYH11 mutation. All patients were addressed to our attention for urinary symptoms, such as urinary retention, urinary tract infections, acute renal injury. Two patients presented frequent stoma prolapses. All children underwent a complete urological evaluation, and then started a bladder management protocol (clean intermittent catheterization, via urethra or cystostomy-tube placement), with improvement of urinary infections, upper urinary tract dilation and stoma prolapses, if present. All patients had good renal function at last follow-up. CONCLUSION: We believe that MMIHS patients must be addressed soon and before onset of symptoms for a multidisciplinary evaluation, including an early assessment by a pediatric urologist expert in functional disorder, to preserve renal function at its best.

Management of urinary incontinence in girls with congenital pouch colon.

PURPOSE: This study describes the management of urinary incontinence (UI) in eight girls with congenital pouch colon (CPC) associated with anorectal malformation (ARM). METHODS: From 2013 to 2015, six girls with CPC and UI underwent bladder neck reconstruction (BNR). Four girls had complete UI (CUI) and two girls partial UI (PUI). From 2019 to 2023, four girls, including two with failed BNR, underwent bladder neck closure (BNC) and augmentation cystoplasty (AC) with a continent stoma. Subtypes of CPC were Complete CPC (n = 7) and Incomplete CPC (n = 1). All girls had a double vagina; short, wide urethra; and reduced bladder capacity with an open, incompetent bladder neck (BNI). During BNR, a neourethra was constructed from a 1.5-2 cm-wide and 1.5-3-cm-long trigonal strip. During BNC, AC was performed using a 20 cm ileal segment (n = 3) and by a colonic pouch segment, preserved during earlier colorraphy (n = 1). Continent stoma included a Monti's channel (n = 3) and appendicovesicostomy (n = 1). RESULTS: BNR produced moderate improvement of UI (n = 2), while UI was still very severe (n = 4). During BNC, intraoperative complications included iatrogenic vaginal tears (n = 4). Early complications included partial dehiscence of the ileocystoplasty (n = 1), partial adhesive small bowel obstruction (n = 1), and difficulty in stomal catheterization with prolonged drainage from the pelvic drain (n = 1). Late complications included unilateral grade II vesicoureteric reflux (n = 2) and vesicovaginal fistula (VVF) (n = 2) needing trans-vaginal closure in one girl. Urinary stones (n = 2) with stomal leakage of urine in one girl needed open cystolithotomy twice (n = 1), and endoscopic lithotripsy (n = 1). At follow-up, all patients have high overall satisfaction with the procedure and their continence status. CONCLUSIONS: BNC with AC and a catheterizable stoma satisfactorily achieves continence in girls with CPC and UI, vastly improving quality of life. If lower urinary tract (LUT) anatomy is favorable, BNR with/without AC can be the initial surgical procedure. BNC should be the primary procedure in girls with unfavorable LUT anatomy and for failed BNR. LEVEL OF EVIDENCE: IV.

Vesico-obturator venous plexus - a rare termination of obturator vein.

Obturator vein usually terminates into the internal iliac vein. Its variations are the cause major bleeding problems in pelvic surgeries. We observed a rare variation in the termination of the right obturator vein. There was a duplication of right obturator vein. Both obturator veins entered the pelvic cavity through the obturator foramen and joined with two vesical veins to form a vesico-obturator plexus. This plexus surrounded the internal iliac artery and terminated into the internal iliac vein. Awareness of this rare variation could be of importance to anatomists, radiologists, gynaecologists, urologists, and orthopaedic surgeons. The plexus might lead to hazardous bleeding in pelvic lymph node clearance procedures, hernia surgeries, gynaecological and orthopaedic procedures in this region. The pelvic fractures too can provoke dramatic retroperitoneal hematomas related to these veins injuries.

Copy number variants suggest different molecular pathways for the pathogenesis of bladder exstrophy.

Bladder exstrophy is a rare congenital malformation leaving the urinary bladder open in the midline of the abdomen at birth. There is a clear genetic background with chromosome aberrations, but so far, no consistent findings apart from 22q11-duplications detected in about 2%-3% of all patients. Some genes are implicated like the LZTR1, ISL1, CELSR3, and the WNT3 genes, but most are not explained molecularly. We have performed chromosomal microarray analysis on a cohort of 140 persons born with bladder exstrophy to look for submicroscopic chromosomal deletions and duplications. Pathogenic or possibly pathogenic microdeletions or duplications were found in 16 patients (11.4%) and further 9 with unknown significance. Two findings were in regions linked to known syndromes, two findings involved the same gene (MCC), and all other findings were unique. A closer analysis suggests a few gene networks that are involved in the pathogenesis of bladder exstrophy; the WNT-signaling pathway, the chromosome 22q11 region, the RIT2 and POU families, and involvement of the Golgi apparatus. Bladder exstrophy is a rare malformation and is reported to be associated with several chromosome aberrations. Our data suggest involvement of some specific molecular pathways.

Bladder duplication in infant girls: role of imaging in two rare cases with variants of a complete sagittal septum.

Bladder duplication is an extremely rare congenital anomaly of the urinary system that is more frequent in boys; the literature is limited to case reports and case series. We describe two cases of bladder duplication in two infant girls with an uncommon variant of complete sagittal septum not included in the Abrahamson classification. The diagnosis was made using magnetic resonance urography, combining excellent anatomical information and static and dynamic evaluation of the urinary tract. The diagnostic information provided by MR-urography was confirmed on surgical exploration. These cases provide an opportunity for paediatric radiologists and urologists to learn more about bladder duplication and improve their diagnosis of this rare condition.

Prenatal Detection of Vesico-Allantoic Cyst: Ultrasound and Autopsy Findings.

Introduction: The vesico-allantoic cyst is a communication between the fetal bladder and the allantois through a patent urachus.Case Report: We describe a 17-week of gestational age (WGA) fetus with a 40 x 30 mm vesico-allantoic cyst. At 19 WGA, ultrasound (US) detected bilateral dilatation of renal pelvis (5-6 mm), hydroureters, and hypospadias. Amniotic fluid, umbilical cord flow, and fetal biometry were regular. Due to uncertain prognosis, the parents opted for legal termination of pregnancy. Autopsy confirmed the prenatal findings, also revealing intestinal malrotation and Meckel's diverticulum.Discussion/Conclusion: Probably an initial urinary tract obstruction occurred, not yet affecting the amniotic fluid volume, but evident as pyelectasis. This case highlights the possibility that genito-urinary and intestinal anomalies may be found in association with the vesico-allantoic cyst.

The Diverse Phenotype of Intestinal Dysmotility Secondary to ACTG2-related Disorders.

BACKGROUND AND AIMS: The initial description of a heterozygous dominant ACTG2 variant in familial visceral myopathy was followed by the identification of additional variants in other forms of intestinal dysmotility disorders. we aimed to describe the diverse phenotype of this newly reported and rare disease. METHODS: Report of 4 new patients, and a systematic review of ACTG2-related disorders. we analyzed the population frequency and used in silico gene damaging predictions. Genotype-phenotype correlations were explored. RESULTS: One hundred three patients (52% girls), from 14 publications, were included. Twenty-eight unique variants were analyzed, all exceedingly rare, and 27 predicted to be highly damaging. The median Combined Annotation Dependent Depletion (CADD) score was 29.2 (Interquartile range 26.3-29.4). Most patients underwent abdominal surgery (66%), about half required intermittent bladder catheterization (48.5%), and more than half were parenteral nutrition (PN)-dependent (53%). One-quarter of the patients died (25.7%), and 6 required transplant (5.8%). Girls had a higher rate of microcolon (P  = 0.009), PN dependency (P = 0.003), and death/transplant (P = 0.029) compared with boys, and early disease onset (<2 years of age) was associated with megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) features. There was no statistical association between disease characteristics and CADD scores. CONCLUSIONS: Damaging ACTG2 variants are rare, often associated with MMIHS phenotype, and overall have a wide phenotypic variation. Symptoms usually present in the perinatal period but can also appear at a later age. The course of the disease is marked by frequent need for surgical interventions, PN support, and mortality. Poor outcomes are more common among girls with ACTG2 variants.

Surgery of the Equine Urinary Tract.

Urinary surgery in the horse may be challenging. More straightforward procedures, such as urinary bladder or urachal defects, do not usually require specialized equipment or imaging, although laboratory work is helpful. Congenital or acquired conditions of the ureters or kidneys may necessitate advanced diagnostic work-ups including advanced imaging /or and minimally invasive procedures. Some surgery of the lower urinary tract is done in the sedated, standing adult horse. Surgery involving the kidney typically requires general anesthesia. Laparoscopy and associated tools are frequently used. Although many of the surgical procedures discussed are quite involved, they are becoming more commonplace.

Five New Cases of Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome (MMIHS), with One Case Showing a Novel Mutation.

BACKGROUND: Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a lethal congenital disorder characterized by a large, non-obstructed bladder, microcolon, and lack of proper peristalsis. MATERIALS AND METHODS: Five cases of MMIHS were identified, confirmed histologically and were predominantly female (F:M, 4:1). DNA sequencing was also performed. RESULTS: Four cases showed mutations in the α3 and ß4 nicotinic acetylcholine receptor (ηAChR) subunits (CHRNA3 and CHRNB4, respectively) on chromosome 15q24. The 5th case had a delayed clinical presentation of intussusception at 11 months and showed a novel missense mutation in ATP2B4 on Chromosome 1q32. CONCLUSION: The first four patients showed a previously identified mutation. The 5th patient shows a novel mutation in ATP2B4. This novel gene was associated with a less severe presentation and increases success of multiorgan transplant than the other four patients. This highlights how identifying various mutations may impact prognosis and clinical treatment plans for MMIHS patients.

Prenatally Ruptured Patent Urachus: A Case Report and Review of Literature.

Patent urachus is a type of urachal anomaly in which the urachus does not tail off but remains connected to the bladder in the umbilicus. The prevalence of patent urachus is very low. Herein, we report a case of patent urachus ruptured and exposed to amniotic fluid in utero. In this case, the size decreased after the second trimester, which was thought to be due to rupture in utero. After delivery, patent urachus was confirmed by inserting a foley catheter, which runs through a ruptured cyst on umbilical cord insertion. The day after delivery, the neonate underwent surgical excision of the urachal cyst and closing umbilicus. The mechanism of patent urachus rupture is unknown. As the fetus matures, it is thought that the higher intravesical pressure may affect the rupture of the cyst. Patent urachus could be ruptured in the uterus spontaneously, and surgical correction is needed. Therefore, prenatal differential diagnosis is important.

[Ectopic duodenal varices as a cause of difficult diagnosis of bleeding in extrahepatic portal hypertension]. / Varikoznye veny dvenadtsatiperstnoi kishki kak prichina «trudno¼ diagnostiruemogo krovotecheniya pri vnepechenochnoi portal'noi gipertenzii.

Bleeding from ectopic varicose veins is a rare life-threatening cause of upper gastrointestinal hemorrhage. Alberti first described duodenal varices in 1931. According to the literature, incidence of duodenal varicose veins in patients with portal hypertension is 1-3% of all varicose veins. Bleeding from duodenal varices makes up 17% of all bleedings from other ectopic varices. Mortality in these patients may be up to 40%. The causes are delayed diagnosis, technical difficulties in endoscopic therapeutic procedures (sclerotherapy, endoscopic ligation), as well as ineffective Blackmore tube for hemorrhage in distal stomach and bowel. We report a rare case of upper gastrointestinal bleeding from ectopic duodenal varices.

Z-scores of fetal bladder size for antenatal differential diagnosis between posterior urethral valves and urethral atresia.

OBJECTIVE: To construct reference values for fetal urinary bladder distension in pregnancy and use Z-scores as a diagnostic tool to differentiate posterior urethral valves (PUV) from urethral atresia (UA). METHODS: This was a prospective cross-sectional study in healthy singleton pregnancies aimed at constructing nomograms of fetal urinary bladder diameter and volume between 15 and 35 weeks' gestation. Z-scores of longitudinal bladder diameter (LBD) were calculated and validated in a cohort of fetuses with megacystis with ascertained postnatal or postmortem diagnosis, collected from a retrospective, multicenter study. Correlations between anatomopathological findings, based on medical examination of the infant or postmortem examination, and fetal megacystis were established. The accuracy of the Z-scores was evaluated by receiver-operating-characteristics (ROC)-curve analysis. RESULTS: Nomograms of fetal urinary bladder diameter and volume were produced from three-dimensional ultrasound volumes in 225 pregnant women between 15 and 35 weeks of gestation. A total of 1238 urinary bladder measurements were obtained. Z-scores, derived from the fetal nomograms, were calculated in 106 cases with suspected lower urinary tract obstruction (LUTO), including 76 (72%) cases with PUV, 22 (21%) cases with UA, four (4%) cases with urethral stenosis and four (4%) cases with megacystis-microcolon-intestinal hypoperistalsis syndrome. Fetuses with PUV showed a significantly lower LBD Z-score compared to those with UA (3.95 vs 8.83, P < 0.01). On ROC-curve analysis, we identified 5.2 as the optimal Z-score cut-off to differentiate fetuses with PUV from the rest of the study population (area under the curve, 0.84 (95% CI, 0.748-0.936); P < 0.01; sensitivity, 74%; specificity, 86%). CONCLUSIONS: Z-scores of LBD can distinguish reliably fetuses with LUTO caused by PUV from those with other subtypes of LUTO, with an optimal cut-off of 5.2. This information should be useful for prenatal counseling and management of LUTO. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Megacystis Microcolon Intestinal Hypoperistalsis Syndrome: A Case Series With Long-term Follow-up and Prolonged Survival.

OBJECTIVES: Describe clinical characteristics, management, and outcome in a cohort of megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) patients. METHODS: We conducted a retrospective chart review of MMIHS patients followed at a large transplant and intestinal rehabilitation center over a period of 17 years. RESULTS: We identified 25 patients with MMIHS (68% girls, 13 transplanted). One transplanted and 1 nontransplanted patient were lost to follow-up. We estimated 100, 100, and 86% for 5-, 10-, and 20-year survival, respectively, with only 1 death. Of the 22 patients alive at the time of study (11 transplanted, 11 nontransplanted), median age was 9.2 years (range 2.7-22.9 years). Longest posttransplant follow-up was 16 years. Seventeen patients had available prenatal imaging reports; all showed distended bladder. Eight had genetic testing (5, ACTG2; 2, MYH11; 1, MYL9). Almost all patients had normal growth with median weight z-score -0.77 (interquartile range -1.39 to 0.26), height z score -1.2 (-2.04 to -0.48) and body mass index z-score 0.23 (-0.37 to 0.93) with no statistical difference between transplanted and nontransplanted patients. All nontransplanted patients were on parenteral nutrition with minimal/no feeds, and all except 1 of the transplanted patients were on full enteral feeds. Recent average bilirubin, INR, albumin, and creatinine fell within the reference ranges. CONCLUSIONS: This is the largest single-center case series with the longest duration of follow-up for MMIHS patients. In the current era of improved intestinal rehabilitation and transplantation, MMIHS patients have excellent outcomes in survival, growth, and liver function. This observation contradicts previous reports and should alter counselling and management decisions in these patients at diagnosis.