Variant in ACTG2 Causing Megacystis Microcolon Hypoperistalsis Syndrome and Severe Familial Postpartum Bleeding

Introduction: Megacystis microcolon hypoperistalsis syndrome (MMIHS) is a rare condition with high morbidity and mortality. It is characterized by megacystis, microcolon, and intestinal hypoperistalsis leading to various grades of bladder and bowel obstruction.

Case presentation: This report describes a pregnant woman with a history of bowel obstruction, urine retention, and heavy postpartum bleeding where ultrasound findings of fetal megacystis during pregnancy led to genetic testing in the family. The fetus, the pregnant woman, and four female family members were heterozygous for a pathogenic variant detected in the ACTG2 gene. The fetus was treated successfully for hydronephrosis using vesicoamniotic shunting.

Discussion: Early diagnosis of a fetus with MMIHS is important to secure multidisciplinary prenatal and neonatal treatment. Furthermore, gene testing must be considered when a woman presents a history of pseudo-obstruction and urine retention to prevent complications during pregnancy and labor. Finally, recurrent familial postpartum bleeding should lead to referral to genetic evaluation.