1012 Sleep disordered breathing in children with Congenital Myasthenic Syndrome

Abstract Introduction Congenital Myasthenic Syndromes (CMS) include a group of heterogeneous disorders encompassing the neuromuscular junction. These disorders have a wide range of clinical presentations according to the degree and group of muscles involved. While some children can present with modest muscle weakness, others present with significant hypotonia, or even respiratory failure. The natural history of CMS, and in particular, the diagnostic role of polysomnography (PSG) in these children, is not well documented. Report of case(s) Retrospective chart review via EMR in a large tertiary center. Patient 1. 19-month-old male with VAMP-1 gene mutation, treated with pyridostigmine, underwent a PSG to evaluate for sleep disordered breathing (SDB). The PSG demonstrated an AHI of 17.7. Repeat PSG post adenoidectomy showed an obstructive apnea hypopnea index (OAHI) 8.6, and central apnea index (CAI) 1.2. He was started on 0.5 LPM oxygen for sleep. Patient 2. 2-year-old female with GFPT1 gene mutation, chronic respiratory failure, tracheostomy/ventilator dependent had a PSG with tracheostomy uncapped on room air which showed an OAHI 1.7, and CAI 0.3. Four years later, split night PSG was started on room air which showed an OAHI 2.8, and CAI 4.6. The ventilator was added at patient’s home settings which improved sleep quality and resolved respiratory events. She was continued on home ventilator settings for sleep despite pharmacological treatment with pyridostigmine. Patient 3. 3-year-old male with CHRNE gene mutation and treated with pyridostigmine. He was evaluated for SDB due to snoring. The PSG demonstrated an OAHI 3.4, and CAI 1.4. Repeat PSG post adenotonsillectomy showed an OAHI 0.4, and CAI 0.4. A third PSG at age 5 was normal. Conclusion We present 3 children with various mutations leading to CMS. The heterogeneity in the clinical course, response to therapy, and outcome may be related to genetic mutations, severity of the disorder and muscles involved, time of diagnosis and medical response to treatment. Polysomnography is an important modality for diagnosis of SDB as well as to monitor response to treatment over time. We conclude that patients with CMS should have a PSG completed given this increased risk. Support (if any)