0798 Reported Sleep Disturbances in Individuals with Christianson Syndrome

Abstract

Introduction: Christianson Syndrome (CS), a recently identified X-linked neurodevelopmental disorder, is caused by mutations in the human gene SLC9A6 encoding the recycling endosomal alkali cation/ proton exchanger NHE6. CS may be among the most common X-linked developmental brain disorders. Individuals with CS have pronounced limitations in cognitive ability, motor skills and adaptive behaviour. Clinically significant sleep problems are prevalent in individuals with neurodevelopmental disorders such as autism and Angelman syndrome which share some phenotypic similarities with CS. There are two reports in the literature pertaining to the association of CS with electrical status epilepticus during slow-wave sleep, but there is currently no information that describes sleep disturbances in individuals with CS. The objective of this study was to characterize, for the first time, sleep disturbances in individuals with CS. Methods: 13 boys with confirmed mutations in NHE6 (Mean Age=12.33 years, SD=6.2) were recruited through the CS Association. Information on age, gender, and patients' medical history was collected using a short questionnaire completed by parents. Sleep disturbances were assessed using the Sleep Disturbance Scale for Children, which investigates the occurrence of sleep problems or disorders during the previous 6 months. The scale includes the following six factors: (1) disorders of initiating and maintaining sleep; (2) sleep-breathing disorders; (3) disorders of arousal, including sleepwalking, sleep terrors, and nightmares; (4) sleep-wake transition disorders, including hypnic jerks, rhythmic movement disorders, hypnagogic hallucinations, nocturnal hyperkinesias, and bruxism; (5) disorders of excessive somnolence; and (6) sleep hyperhidrosis. A T score ; 70 is considered abnormal. Results: The most typical sleep problems were disturbances of initiating or maintain sleep (46%) and sleep-wake transition (31%). In addition, arousal or breathing problems occurred in 7% of the participants. Conclusion: We present results from the largest sample reported in the literature regarding individuals with CS to date. Our findings suggest that disturbances of initiating or maintaining sleep and sleep wake transition are prevalent in this population, and emphasise the need for assessing sleep in individuals with CS.