ACTG2 and megacystis-microcolon-intestinal hypoperistalsis syndrome 1: The following genes are known to be involved in pathogenesis of MMIHS: ACTG2 (the most frequent), MYH11 (myosin heavy chain 11), MYLK (myosin light chain kinase), LMOD1 (leiomodin 1), and MYL9 (myosin light chain 9) [3].