Mydriasis in association with MMIHS in a female infant: evidence for involvement of the neuronal nicotinic acetylcholine receptor.

We report a case of megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS), occurring in association with mydriasis, in a female infant born to consanguineous Asian parents. This association has not previously been reported and is of interest because mydriasis has been found in a murine MMIHS model produced by knockout of the genes coding for the alpha3 subunit or the beta2 and beta4 subunits of the neuronal nicotinic acetylcholine receptor. This may provide an important clue to the genetic basis of MMIHS in humans.