Familial megacystis microcolon intestinal hypoperistalsis syndrome: a systematic review

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a rare and severe disorder of functional obstruction affecting bladder and bowel, usually diagnosed in the neonatal period. Over 230 cases have been reported since Berdon and colleagues first described this clinical entity in 1976. The exact pathogenesis of MMIHS is unknown. Familial occurrence of MMIHS has been reported and could offer insight into the aetiology of this disease. The purpose of this study was to systematically review the published literature for the evidence of familial MMIHS and to characterise these presentations.

A literature search was performed using the keywords "megacystis microcolon intestinal hypoperistalsis" (1976-2013). Retrieved articles, including additional studies from reference lists, were reviewed for consanguinity between parents and recurrence of MMIHS between siblings. Data were extracted for cases where familial MMIHS was present.

A total of 47 patients were reported in which familial MMIHS was likely or confirmed. 15 sibling sets were definitively diagnosed with MMIHS (14 pairs and one set of three siblings). Four further index patients with a confirmed diagnosis and also one of the sibling pairs were reported to have a sibling in which MMIHS was probable. Consanguinity between parents was present in four of the confirmed sibling sets and in an additional seven individual cases. The outcome for familial MMIHS is generally poor. Multiple sibling fatalities were frequent and in only one family were both siblings' survivors at the time of reporting.

Consanguinity between parents and recurrence in siblings indicate that MMIHS is inherited in an autosomal recessive manner. With the advent of next generation sequencing, these familial clusters may be key to determining the genetic basis for MMIHS.