1246 Recurrent Apneic Events in a Premature Infant – An Unusual Presentation of Rett Syndrome

Abstract

Introduction: MECP2 related disorders overwhelmingly occur in females. Three variants have been described: 1) Classic Rett syndrome, a neurodevelopmental disorder with apparently normal psychomotor development until 18 months of life, followed by regression in language and motor skills; 2) Atypical Rett syndrome, identified in patients with learning or intellectual disabilities along with motor findings of tremor or spasticity; and 3) Severe neonatal encephalopathy, described mainly in affected males with death before 2 years of age. Herein we present a case of the severe encephalopathy phenotype in a female infant with central sleep apnea. Report of Case: We report a case of a 7 month old girl with a history of 29 week prematurity and bronchopulmonary dysplasia who presented with recurrent apneic spells at home during wakefulness and sleep, some requiring cardiopulmonary resuscitation. Polysomnography revealed a total apnea-hypopnea index (AHI) of 26.1/hour, obstructive AHI of 5.2/hour, central index of 20.9/ hour, and end-tidal CO2 levels greater than 50mmHg for 48.8 % of the total sleep time (worse during NREM). A diagnosis of central hypoventilation was confirmed. Testing for Phox 2B was negative. Full genome sequencing reported a mutation in the MECP2 gene. Additional workup revealed a patent ductus arteriosus, cortical visual impairment and EEG findings of encephalopathy without seizure activity. A tracheostomy was performed and respiratory support with mechanical ventilation was initiated. Conclusion(s): Although congenital central hypoventilation syndrome is a common cause of central hypoventilation in infancy, other etiologies must be considered in the differential diagnosis especially when testing is inconclusive. The presence of central sleep apnea in older females with Classic Rett syndrome has been reported. However, presentation during infancy in a female (as in our case) is rare.