Visceral myopathies are characterized by smooth muscle cell abnormalities and are most commonly caused by mutations in the contractile apparatus cytoskeletal proteins (for an extensive review, see [43]), such as ACTG2 [16,20], ACTA2 [19], MYH11 [26,44], MYLK [28], LMOD1 [25], MYL9 [45], and FLNA [22,23,46]. The gene discussed is ACTG2; the disease is familial visceral myopathy.