307 Phenotypic-genotypic expansion of plectinopathy in a patient with muscular dystrophy and immune-mediated myasthenia gravis

A 26-year-old female presented with blistering skin lesions since infancy, hair loss, proximal motor weakness, nasal tone speech, swallowing problem, and droopy eyes. Upon neurological examination, normal cognition, inability to walk unassisted, bilateral ptosis a full range of extraocular movements, weak gag reflex, generalized muscle atrophy, decreased deep tendon reflexes were detected. Her electromyography revealed small polyphasic unit action potentials, minimal insertional activities, myopathic changes, motor, sensory increased latency, amplitude, reduced velocity, F wave. These findings compatible neuromuscular junction disorder, i.e., myasthenia gravis (MG) muscular dystrophy. The acetylcholine receptor antibody test titer 2.36 nmol/L (normal range: ≤ 0.4 nmol/L). serum creatine phosphokinase was 422 IU/L which higher than normal. nature epidermolysis bullosa. Whole-exome sequencing performed the clinical suspicion muscle-related plectinopathy in novel homozygous nonsense variant PLEC identified. Besides, biopsy staining Hematoxylin Eosin, modified Gomori Trichrome, Cytochrome c oxidase + Succinate dehydrogenase, Nicotinamide adenine dinucleotide, dehydrogenase-tetrazolium reductase showed chronic atrophic necrosis/regeneration, internalization nuclei, severe endomysial fibrosis. pathological She treated stepwise incremental dose steroid up 30 mg/day for 6 weeks resulted significant improvement her addition ptosis. MG composite scale from 22 12. combination dystrophy immune-based molecular are this case mutations.