X-linked protocadherin 19 mutations cause female-limited epilepsy and cognitive impairment

Nat Genet. 2008 Jun;40(6):776-81. doi: 10.1038/ng.149. Epub 2008 May 11.

Abstract

Epilepsy and mental retardation limited to females (EFMR) is a disorder with an X-linked mode of inheritance and an unusual expression pattern. Disorders arising from mutations on the X chromosome are typically characterized by affected males and unaffected carrier females. In contrast, EFMR spares transmitting males and affects only carrier females. Aided by systematic resequencing of 737 X chromosome genes, we identified different protocadherin 19 (PCDH19) gene mutations in seven families with EFMR. Five mutations resulted in the introduction of a premature termination codon. Study of two of these demonstrated nonsense-mediated decay of PCDH19 mRNA. The two missense mutations were predicted to affect adhesiveness of PCDH19 through impaired calcium binding. PCDH19 is expressed in developing brains of human and mouse and is the first member of the cadherin superfamily to be directly implicated in epilepsy or mental retardation.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / growth & development
  • Brain / metabolism
  • Brain / pathology
  • Cadherins / genetics*
  • Case-Control Studies
  • Chromosomes, Human, X*
  • Codon, Nonsense / genetics*
  • Cognition Disorders / genetics*
  • Cognition Disorders / pathology
  • Epilepsy / genetics*
  • Epilepsy / pathology
  • Female
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Gene Expression Regulation, Developmental
  • Genes, X-Linked / genetics
  • Genomic Imprinting*
  • Humans
  • In Situ Hybridization
  • Male
  • Mental Retardation, X-Linked / genetics
  • Mental Retardation, X-Linked / pathology
  • Mice / embryology
  • Mutation, Missense / genetics*
  • Pedigree
  • Phenotype
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Skin / cytology
  • Skin / metabolism

Substances

  • Cadherins
  • Codon, Nonsense
  • PCDH19 protein, human
  • RNA, Messenger