Phenotypic expansion of visceral myopathy associated with ACTG2 tandem base substitution.

Klar J, Raykova D, Gustafson E, Tóthová I, Ameur A, Wanders A, Dahl N

Eur. J. Hum. Genet. 23 (12) 1679-1683 [2015-12-00; online 2015-03-19]

Familial visceral myopathy (FVM) is a rare heritable and heterogeneous condition due to impaired smooth muscle function. We identified a family segregating 11 individuals with a spectrum of visceral symptoms involving the small intestine, colon, biliary tract, urinary tract and uterus. Whole-exome sequencing revealed a novel heterozygous tandem base substitution c.806_807delinsAA (p.(Gly269Glu)) in ACTG2, encoding smooth muscle actin γ-2, in affected family members. Variants in ACTG2 were recently identified in FVM with intestinal pseudo-obstruction as well as with the congenital megacystics-microcolon-intestinal hypoperistalsis syndrome. In our family, eight affected members presented with severe complications from the biliary and/or the urinary tracts in addition to gastrointestinal pseudo-obstructions. Furthermore, all affected mothers had a history of assisted deliveries owing to poor progress during labor and weak uterine contractions. The variable involvement of multiple smooth muscle-dependent organs in our family, including the biliary tract and the uterus, add to the phenotypic spectrum associated with ACTG2 missense variants.

NGI Uppsala (Uppsala Genome Center)

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PubMed 25782675

DOI 10.1038/ejhg.2015.49

Crossref 10.1038/ejhg.2015.49

ejhg201549

pmc PMC4795199