Cortical Myoclonus and Complex Paroxysmal Dyskinesias in a Patient with NAA15 Variant

作者：Elena Freri, Laura Canafoglia, Claudia Ciaccio, Davide Rossi Sebastiano, Davide Caputo, Roberta Solazzi, Francesca L. Sciacca, Maria Iascone, Ferruccio Panzica, Tiziana Granata, Silvana Franceschetti, Nardo Nardocci · 发表于：Movement Disorders · 年份：2024 · DOI：10.1002/mds.29793 · 被引用次数：5 · 研究领域：Genetics and Neurodevelopmental Disorders、Neurological disorders and treatments、Glycogen Storage Diseases and Myoclonus

NAA15 gene encodes for a protein involved in amino-terminal acetylation of cytosolic proteins. Patients with NAA15 variants show variable levels of intellectual disability, dysmorphic features, cardiac and visual anomalies, and movement disorders, including pediatric-onset dystonia and dystonia parkinsonism.1-3 We report the clinical and neurophysiological characteristics observed in a young girl harboring a novel pathogenic NAA15 variant. The girl was born at term, from healthy parents, after a normal pregnancy; during adolescence, she reported episodes of tachycardia, without any significant findings on cardiac examinations. From the age of 12 years, she complained the appearance of stiffness and “tremor” in her right, dominant, hand that used to occur after a prolonged period (5–10 minutes) of writing and that disappeared after some minutes of rest. At the time of our first observation, at age 15, during upper-limb extension, we noticed irregular, arrhythmic, small-amplitude dyskinesias resembling myoclonus. The dyskinesias were absent at rest. Clinical examination did not detect somatic abnormalities, and cognitive evaluation reported IQ 72 on the Wechsler scale and specific learning disorder. Video electroencephalogram–electromyogram (EEG–EMG) recording identified short sequences of repetitive EMG bursts lasting less than 50 ms, intermingled with normal contraction (Fig. 1A). Coherence analysis indicated that the bursts were synchronous on the antagonist muscle couples (...