Megacystis Microcolon Hypoperistalsis Syndrome (MMIHS) is a rare disorder with a smooth muscle myopathy.

Synonym: Berdon Syndrome



(1) autosomal recessive: LMOD1, MYH11, MYL9, MYLK

(2) autosomal dominant: ACTG2


Most patients are female (4:1 to males).


Key features:

(1) megacystis in the absence of mechanical obstruction, with inability to void

(2) microcolon

(3) small bowel hypoperistalsis


Other findings:

(1) abdominal distention

(2) absent or decreased bowel sounds

(3) failure to pass meconium

(4) bilious vomit

(5) variable esophageal dysmotility

(6) variable facial dysmorphism (cleft palate, partial blindness, partial deafness)

(7) hydronephrosis and recurrent urinary tract infections

(8) variable malformations (cardiovascular, genitourinary, skeletal, neurologic)

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