CONGENITAL MYOPATHIES 1 – NEMALINE: P.18 KBTBD13, NEM6 congenital myopathy: deep muscle phenotyping reveals ring-rods fibers, nuclear clumps, and protein aggregates as new morphologic markers

Abstract

Nemaline myopathy type 6 (NEM6) is a rare congenital myopathy characterized by muscle weakness, exercise intolerance and muscle slowness, linked to autosomal dominant KBTBD13 gene mutations. Mutated KBTBD13 interacts improperly with thin filaments/actin provoking impaired muscle-relaxation kinetics. We performed a deep muscle phenotyping including immunohistochemistry and electron microscopy in 18 muscle biopsies of Dutch NEM6 patients in order to correlate muscle morphology with clinical phenotype and pathophysiological mechanisms.