Cap Myopathy With a Heterozygous TPM3 Missense Mutation

ABSTRACT

Cap myopathy is pathologically characterized by cap structures comprising well-demarcated areas under the sarcolemma and containing deranged myofibrils and scattered Z-disks. Clinically it presents with slowly progressive muscle weakness, myopathic face, and frequent respiratory insufficiency. Four genes have been reported to be associated with the disease TPM2, TPM3, ACTA1, and NEB. Here we describe that a patient presenting with mild limb weakness with facial affection showed cap structures on muscle pathology and carried a heterozygous TPM3 mutation.