Segregation of a Missense Variant in Enteric Smooth Muscle Actin γ-2 With Autosomal Dominant Familial Visceral Myopathy

We identified the R148S variant in ACTG2 as a cause of FVM in one family. The altered ACTG2 protein appears to aggregate, rather than form actin filaments, in intestinal smooth muscle tissue. This defect could impair contraction of the visceral smooth muscle cells and reduce bowel motility.