Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome: Case Report and Review of Prenatal Ultrasonographic Findings

Abstract

Objective: To investigate prenatal ultrasonographic findings associated with megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS). Methods: A PubMed search was performed using the terms ‘MMIHS', ‘MMIH' and ‘prenatal diagnosis'. Results: A total of 50 cases were analyzed. Prenatal diagnosis was achieved in 26% of cases. In 54% of patients with a correct antenatal diagnosis there was a previously affected sibling. Fetal megacystis with or without hydroureteronephrosis was the most common initial ultrasonographic finding (88%). While megacystis eventually complicated all fetal presentations, isolated bilateral hydronephrosis and isolated dilated stomach were noted (in 10 and 2% of cases, respectively) prior to megacystis. The initial sonographic abnormality was most commonly detected (in 70% of patients) in the second trimester. Amniotic fluid was normal in 69% and increased in 27% of cases. Gastrointestinal abnormalities were noted in 24% of pregnancies. Conclusion: MMIHS should be prenatally suspected when fetal megacystis is associated with a normal or increased amount of amniotic fluid and normal external genitalia, especially in the setting of a suggestive family history. Associated gastrointestinal findings support this diagnosis. Isolated bilateral hydronephrosis may precede the development of megacystis. Due to preserved renal function and a general absence of oligohydramnios, no rationale exists for vesicoamniotic shunt placement.

The usefulness of whole-exome sequencing in routine clinical practice

“…A de novo mutation in MYH10 that causes a similar phenotype in mouse models; in our patient it caused microcephaly, hydrocephalus, developmental delay, right-cranial V and VII nerve palsy, strabismus, nystagmus, intrauterine growth restriction, failure to thrive, congenital unilateral dysplastic kidney, congenital bilateral hip dislocation with abnormal acetabular development, and bilateral vertical talus. 13 We also identified a de novo mutation in SNAP25 associated with epilepsy and static encephalopathy. 14 We identified a homozygous mutation in GPT2 in a patient with developmental delay and microcephaly who has two similarly affected siblings.…”

New Insights into the Genetics of Fetal Megacystis: ACTG2 Mutations, Encoding γ-2 Smooth Muscle Actin in Megacystis Microcolon Intestinal Hypoperistalsis Syndrome (Berdon Syndrome)

“…We have previously reported on prenatal sonographic findings associated with MMIHS and delineated features that might be useful in distinguishing fetal megacystis associated with MMIHS [15]. Overall, fetal megacystis associated with MMIHS presents in the second trimester, although reports on its presence in the first trimester have also been published [34].…”

“…In the remaining cases, fetal renal hydronephrosis or a fetal dilated stomach usually precedes the development of fetal megacystis. The amniotic fluid volume remains normal or is increased in the majority of cases, indicating preserved overall renal function [15]. …”

“…The prenatal ultrasonographic findings of the affected individuals in family 1 were described in detail elsewhere [15] and are summarized in table 1. The proband in family 1, a female child from a nonconsanguineous Chinese family, presented with fetal megacystis during the second trimester as well as evidence of an echogenic bowel.…”

Megacystis microcolon intestinal hypoperistalsis syndrome presenting as acute intestinal obstruction in 4-days male neonate: A rare case report

“…Screening with USG and fetal magnetic resonance (MR) may prove helpful in antenatal diagnosis. Enlargement of bladder was the most common finding on prenatal USG and can be detected as early as 16 th week of gestation [8]. Although no radiological finding is pathognomonic, prenatal diagnosis is mandatory for optimal counseling and instituting early postnatal treatment of MMIHS.…”