Nemaline Myopathy Associated with Monoclonal Gammopathy - a Case Report

Nemaline (rod) myopathy is an uncommon muscle disease with a wide spectrum of phenotypes. Since 1966 until 2008, 71 patients with sporadic late-onset nemaline myopathy have been described. Among them, 12 had monoclonal gammopathy. This case report describes a 64-year-old man with IgG kappa monoclonal gammopathy of undetermined significance, who developed progressive muscle weakness and symmetric hypotrophy, mainly of the proximal limb muscles a year after diagnosis. Muscle biopsy and electron microscopy revealed the presence of numerous typical rod-shaped inclusions in muscle fibers and the diagnosis of nemaline myopathy was established. The patient did not respond to therapy with corticosteroids, application of IVIG had also been considered. The case report is supplemented with basic information related to sporadic late-onset nemaline myopathy.