Smooth muscle motility disorder phenotypes: A systematic review of cases associated with seven pathogenic genes (, , , , , and ).

Smooth muscle disorders affecting both the intestine and the bladder have been known for a decade. However, the recent discovery of genes associated with these dysfunctions has led to the description of several clinical phenotypes. We performed a systematic review of all published cases involving seven genes with pathogenic variants, , , , , , and , and included 28 articles describing 112 patients and 5 pregnancies terminated before birth. The most commonly described mutations involved (75/112, 67% of patients), (14%) and (13%). Twenty-seven patients (28%) died at a median age of 14.5 months. Among the 76 patients for whom this information was available, 10 (13%) had isolated chronic intestinal pseudo-obstruction (CIPO), 17 (22%) had isolated megacystis, and 48 (63%) had combined CIPO and megacystis. The respective proportions of these phenotypes were 9%, 20% and 71% among the 56 patients with mutations, 20%, 20% and 60% among the 10 patients with mutations and 50%, 50% and 0% among the 7 patients with mutations.