Intestinal pseudo‐obstruction with deficient smooth muscle α‐actin

Abstract

We describe a 48‐year‐old woman with chronic constipation since early childhood who has an intestinal myopathy associated with a hitherto undescribed absence by immunostaining of smooth muscle α‐actin confined to the intestinal circular muscle. There were no abnormalities in other contractile proteins (myosin, tropomyosin, filamin, caldesmon or desmin) and despite the abnormality of a contractile protein isoform in the circular muscle, no significant morphological changes were identified by light microscopy or ultrastructural examination. A possible developmental mechanism for the observed change is proposed. The use of specific antibodies to isoforms of contractile proteins may have potenti..