Autosomal Recessive ACTG2-Related Visceral Myopathy in Brothers.

This case demonstrates that monoallelic hypomorphic variants may underly mild primary gastrointestinal symptoms, while biallelic mild variants can cause severe diseases. The Deletions of the noncoding exon can be an under-recognized cause of mild gastrointestinal symptoms unidentifiable by exome sequencing, explaining some instances of interfamilial variability with an apparent autosomal dominant inheritance. Genome sequencing is recommended as a genetic work-up for primary or idiopathic PIPO because of genetic heterogeneity.