Megacystis microcolon intestinal hypoperistalsis syndrome

The megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) (also known as the Berdon syndrome) is a rare congenital disorder characterized by a dilated non-obstructive urinary bladder and hypoperistalsis of the gastrointestinal tract.

Epidemiology

There is recognised strong female predilection

Pathology

The disorder is thought to arise from defective  primarily affecting the gastrointestinal and renal tracts ¹¹.

Genetics

The disease carries an autosomal recessive inheritance ^2-3 with the a gene locus at 15q24 ⁸ although some authors suggest a sporadic occurence in certain cases ^{reference required}

Associations

• polyhydramnios : can be present in ~ 25 % of cases
• omphalocoele :
• intestinal malrotation ¹⁰

Radiographic features

Antenatal ultrasound

Direct sonographic findings can include

• fetal megacystis
• fetal megaureter
• fetal renal pelvic dilatation
• dilatated segments of bowel (including stomach) - fetal bowel dilatation

Ancilliary sonographic features include

• presence of polyhydramnios 
• presence of normal amniotic volumes in the context of the above renal tract findings

In the context of obstructive "like" renal findings, the presence presence of normal to elevated amniotic fliud volumes may suggest towards the diagnosis. 

Treatment and prognosis

The overall prognosis is consided to be poor and treatment has been shown to be generally ineffective ⁶. It is usually lethal within the first year of life ³.

Etymology

First described by W E Berdon in 1976 ⁴

Differential diagnosis

For antenatal hydronephrosis with hydroureter : consider

• prune belly syndrome : tends to be associated with oligohydramnios
• posterior urethral valves : also tends to be associated with oligohydramnios