Filamin C-Associated Nemaline Myopathy

Pathogenic variants in FLNC are associated with myofibrillar myopathy manifesting with either limb girdle-predominant or distal-predominant weakness. 1A 71-year-old man presented with mild generalized fatigue.Neurologic examination showed asymmetric scapuloperoneal weakness, with bilateral scapular winging, and mild-to-moderate weakness of arm adduction, hip flexion, ankle dorsiflexion, and paraspinals.He had a normal creatine kinase level and no monoclonal gammopathy in serum or urine.Trapezius muscle biopsy (Figure ) showed a nemaline myopathy, with no evidence of a myofibrillar myopathy.Genetic testing showed a pathogenic intronic variant, c.970-4A>G in FNLC, affecting splice region.This is a unique presentation of FLNC myopathy manifesting with scapuloperoneal weakness and a nemaline myopathy on muscle biopsy.A single other case of FLNC-associated nemaline myopathy presenting with predominantly distal weakness has been reported to date. 2 FLNC should be considered in patients with nemaline myopathy.Go to Neurology.org/Nfor full disclosures.