Megacystis Microcolon Intestinal Hypoperistalsis Syndrome: Case Reports and Discussion of the Literature

Abstract

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a rare intestinal dysmotility condition that also involves a dilated urinary bladder. It was believed to be an autosomal recessive condition, but genetic studies have suggested possibly an autosomal dominant inheritance pattern. Prenatal diagnosis can be challenging, but MRI and amniotic fluid/digestive fluid studies may be complementary investigations to improve diagnostic accuracy. Prognosis of MMIHS is generally poor and treatment is mostly supportive. To date, bowel transplantation remains the only viable treatment to restore bowel motility. Here we present two additional cases to contribute towards the scant literature on this condition.

Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome: A Case Report of an Uncommon Condition

“…However, it has been proposed that the absence of bladder emptying after 45 minutes can be a marker of megacystis during gestation [15]. Other findings described in prenatal imaging are dilations of the urinary tract and stomach, with normal amniotic fluid or with polyhydramnios [8,14]. In vesicocentesis, the concentrations of sodium and chloride will be normal, suggesting preserved renal function [10].…”

“…It is characterized by gastrointestinal and genitourinary dysmotility, resulting in its main manifestations: megacystis, microcolon, and decreased peristalsis. Additionally, it is often accompanied by multiple alterations, especially gastrointestinal and genitourinary, such as esophageal dilatation, stomach dilatation, dilated loops of the small intestine, intestinal malrotation, urinary tract dilatation, and vesicoureteral reflux [4][5][6][7][8][9]. Most patients are diagnosed after birth, but prenatal diagnosis is possible in up to 25% of cases based on ultrasound findings [4,8].…”

“…Additionally, it is often accompanied by multiple alterations, especially gastrointestinal and genitourinary, such as esophageal dilatation, stomach dilatation, dilated loops of the small intestine, intestinal malrotation, urinary tract dilatation, and vesicoureteral reflux [4][5][6][7][8][9]. Most patients are diagnosed after birth, but prenatal diagnosis is possible in up to 25% of cases based on ultrasound findings [4,8]. Imaging studies are essential for diagnosis, but genetic testing is necessary to detect underlying mutations that may influence prognosis and family counseling [2].…”

Incidental diagnosis of mucopolysaccharidosis type I in an infant with chronic intestinal pseudoobstruction by exome sequencing

“…Most common symptoms are abdominal distension, absent or decreased bowel sounds, failure to pass meconium and inability to avoid requiring catheterization. Patients undergo surgical interventions such as enterostomies (gastrostomy, jejunostomy) for nutrition administration and bowel decompression, and total parenteral nutrition can be required due to intestinal failure from intestinal dysmotility [ [21] , [22] , [23] ]. Furthermore, recent studies incriminated dominant MYH11 causal variants in CIPO [ 24 ] and in severe gastrointestinal dysmotility [ 25 ].…”

Ultrasound prenatal diagnosis of typical megacystis, microcolon, intestinal hypoperistalsis syndrome

“…MMIHS is considered part of the spectrum of visceral myopathy . De novo and familial cases have been documented, and both autosomal recessive and autosomal dominant inheritances have been proposed for MMIHS . Recently, genetic mutations responsible for the two types of MMIHS (autosomal dominant and autosomal recessive) have been identified.…”