An SCN9A Channelopathy Causes Congenital Inability to Experience Pain

Nature. 2006 Dec 14;444(7121):894-8. doi: 10.1038/nature05413.

Abstract

The complete inability to sense pain in an otherwise healthy individual is a very rare phenotype. In three consanguineous families from northern Pakistan, we mapped the condition as an autosomal-recessive trait to chromosome 2q24.3. This region contains the gene SCN9A, encoding the alpha-subunit of the voltage-gated sodium channel, Na(v)1.7, which is strongly expressed in nociceptive neurons. Sequence analysis of SCN9A in affected individuals revealed three distinct homozygous nonsense mutations (S459X, I767X and W897X). We show that these mutations cause loss of function of Na(v)1.7 by co-expression of wild-type or mutant human Na(v)1.7 with sodium channel beta(1) and beta(2) subunits in HEK293 cells. In cells expressing mutant Na(v)1.7, the currents were no greater than background. Our data suggest that SCN9A is an essential and non-redundant requirement for nociception in humans. These findings should stimulate the search for novel analgesics that selectively target this sodium channel subunit.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cell Line
  • Chromosomes, Human, Pair 2 / genetics
  • Female
  • Humans
  • Male
  • Molecular Sequence Data
  • Mutation / genetics
  • NAV1.7 Voltage-Gated Sodium Channel
  • Pain / genetics*
  • Pain / physiopathology*
  • Pain Insensitivity, Congenital / genetics*
  • Pain Insensitivity, Congenital / physiopathology*
  • Patch-Clamp Techniques
  • Pedigree
  • Phenotype
  • Physical Chromosome Mapping
  • Sodium Channels / chemistry
  • Sodium Channels / genetics*
  • Sodium Channels / metabolism*

Substances

  • NAV1.7 Voltage-Gated Sodium Channel
  • SCN9A protein, human
  • Sodium Channels

Associated data

  • GENBANK/DQ857292