Autosomal recessive inheritance of MMIHS (OMIM 249210) has been suggested in numerous cases based on the presence of two affected siblings [3], [13], [14], consanguinity [15] or both [16]–[19], but no genes have been identified to date, although in retrospect a report of a dominant mutation in the ACTG2 enteric actin gene in a Finnish family with adult onset visceral myopathy has proved to be relevant [20]. Here, ACTG2 is linked to megacystis-microcolon-intestinal hypoperistalsis syndrome 1.