A PRPH splice-donor variant associates with reduced sural nerve amplitude and risk of peripheral neuropathy

Nat Commun. 2019 Apr 16;10(1):1777. doi: 10.1038/s41467-019-09719-4.

Abstract

Nerve conduction (NC) studies generate measures of peripheral nerve function that can reveal underlying pathology due to axonal loss, demyelination or both. We perform a genome-wide association study of sural NC amplitude and velocity in 7045 Icelanders and find a low-frequency splice-donor variant in PRPH (c.996+1G>A; MAF = 1.32%) associating with decreased NC amplitude but not velocity. PRPH encodes peripherin, an intermediate filament (IF) protein involved in cytoskeletal development and maintenance of neurons. Through RNA and protein studies, we show that the variant leads to loss-of-function (LoF), as when over-expressed in a cell line devoid of other IFs, it does not allow formation of the normal filamentous structure of peripherin, yielding instead punctate protein inclusions. Recall of carriers for neurological assessment confirms that from an early age, homozygotes have significantly lower sural NC amplitude than non-carriers and are at risk of a mild, early-onset, sensory-negative, axonal polyneuropathy.

Publication types

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

MeSH terms

  • Adult
  • Age of Onset
  • Aged
  • Axons / pathology
  • Case-Control Studies
  • Cell Line
  • Female
  • Follow-Up Studies
  • Genome-Wide Association Study
  • Homozygote
  • Humans
  • Iceland / epidemiology
  • Loss of Function Mutation
  • Male
  • Middle Aged
  • Neural Conduction / genetics*
  • Peripherins / genetics*
  • Polyneuropathies / epidemiology
  • Polyneuropathies / genetics*
  • Polyneuropathies / physiopathology
  • Prevalence
  • RNA Splice Sites / genetics*
  • RNA Splicing / physiology
  • Sural Nerve / physiopathology*

Substances

  • PRPH protein, human
  • Peripherins
  • RNA Splice Sites