BACKGROUND: Mutations of SLC9A6 may cause an X-linked clinical syndrome first 
described by Christianson in 1999 in which affected males exhibited profound 
intellectual disability, autism, drug-resistant epilepsy, ophthalmoplegia, mild 
craniofacial dysmorphism, microcephaly, and ataxia.
METHODS: We describe a child with an SLC9A6 mutation and an 
electroencephalographic pattern consistent with electrographic status 
epilepticus of sleep.
RESULTS: Our patient's electrographic status epilepticus of sleep resolved after 
treatment with felbamate. Following treatment, he remained seizure-free but did 
not make significant or lasting gains in language.
CONCLUSION: Our report extends the clinical epilepsy phenotype in children with 
SLC9A6 mutations to include electrographic status epilepticus of sleep. In 
addition, felbamate was an effective treatment for electrographic status 
epilepticus of sleep in our patient.