ACTG2-Related Visceral Myopathy: Case Reports with Phenotypic Variations and Review of the Previously Published Cases

Abstract

Background: ACTG2 (smooth muscle actin γ-2) is a gene associated with smooth muscle function. Introduction: Variants in this gene can lead to visceral myopathy (VM), which is a spectrum of various disorders affecting smooth muscle in different parts of the body. There is gap in the literature regarding understanding the full scope of ACTG2-related VM. Patients and methods: Here we present the clinical and molecular investigation of three patients with visceral smooth muscle diseases carrying pathogenetic variants in the ACTG2 gene. Discussion and conclusion: The severity of the disease varies in great extent, even among monochorionic twins sharing same mutation and intrauterine environment, suggesting that second-site factors are likely to impact disease manifestations.

Keywords: ACTG2; case report; intestinal pseudo-obstruction; megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS); monochorionic twins; prenatal diagnosis; visceral myopathy.