A novel mutation in the endosomal Na+/H+ exchanger NHE6 (SLC9A6) causes Christianson syndrome with electrical status epilepticus during slow-wave sleep (ESES)

Epilepsy Res. 2014 May;108(4):811-5. doi: 10.1016/j.eplepsyres.2014.02.009. Epub 2014 Feb 19.

Abstract

Mutations in the solute carrier family 9, subfamily A member 6 (SLC9A6) gene, encoding the endosomal Na+/H+ exchanger 6 (NHE6) are associated with Christianson syndrome, a syndromic form of X-linked intellectual disability characterized by microcephaly, severe global developmental delay, autistic behavior, early onset seizures and ataxia. In a 7-year-old boy with characteristic clinical and neuroimaging features of Christianson syndrome and epileptic encephalopathy with continuous spikes and waves during sleep, we identified a novel splice site mutation (IVS10-1G>A) in SLC9A6. These findings expand the clinical spectrum of the syndrome and indicate NHE6 dysfunction as a new cause of electrical status epilepticus during slow-wave sleep (ESES).

Keywords: Christianson syndrome; ESES; NHE6; SLC9A6.

Publication types

  • Case Reports

MeSH terms

  • Ataxia / genetics*
  • Ataxia / physiopathology
  • Child
  • Epilepsy / genetics*
  • Epilepsy / physiopathology
  • Genetic Diseases, X-Linked / genetics*
  • Genetic Diseases, X-Linked / physiopathology
  • Humans
  • Intellectual Disability / genetics*
  • Intellectual Disability / physiopathology
  • Male
  • Microcephaly / genetics*
  • Microcephaly / physiopathology
  • Mutation*
  • Ocular Motility Disorders / genetics*
  • Ocular Motility Disorders / physiopathology
  • Sleep / genetics*
  • Sodium-Hydrogen Exchangers / genetics*
  • Status Epilepticus / genetics*
  • Status Epilepticus / physiopathology

Substances

  • SLC9A6 protein, human
  • Sodium-Hydrogen Exchangers

Supplementary concepts

  • Mental Retardation, X-Linked, Syndromic, Christianson Type