127 ACTA1 associated myopathy with neurogenic EMG changes

BackgroundWe describe a proband and her son who have proximal limb and facial weakness and marked hand involvement. A congenital myopathy panel demonstrated two RYR1 variants and the p.Ile289Phe novel variant in ACTA1.Cases: The proband had initially been diagnosed with SMA following premature birth, late milestones, scoliosis and proximal and distal weakness which was relatively static until age 40. EMG as a child was neurogenic. Her son had poor feeding after birth, delayed motor milestones, intellectual delay, and by his teens, severe facial weakness and distal upper limb wasting particularly the finger flexors and extensors, with hip flexion of grade 3. Repeat neurophysiological evaluation of the proband at age 60, demonstrated a neurogenic pattern but also brief polyphasic motor units, raising suspicion of an addi- tional myopathic process.DiscussionZukosky and colleagues1also described a family with a different missense mutation in the ACTA1 gene who had been diagnosed with SMA on the basis of neurogenic EMG findings. Our additional family confirms that myopathy can be accompanied by neurogenic EMG changes in ACTA1 associated myopathy.Reference1. Zukosky K, Meilleur K, Traynor BJ, Dastgir J, Medne L, Devoto M, et al. Association of a Novel ACTA1 Mutation With a Dominant Progressive Scapuloperoneal Myopathy in an Extended Family. JAMA Neurol. 2015 Jun 1;72(6):689–98.carolynnedoherty@doctors.org.uk|NIHR Bursary