A novel missense mutation in ACTG1 causes dominant deafness in a Norwegian DFNA20/26 family, but ACTG1 mutations are not frequent among families with hereditary hearing impairment

N. D Nanna D Rendtorff, Mei Zhu, Toril Fagerheim, Torben L. Antal, Mary Pat Jones, Tanya M. Teslovich, Elizabeth M. Gillanders, Michael Barmada, Erik Teig, Jeffrey M. Trent, Karen H. Friderici, Dietrich A. Stephan, Lisbeth Tranebjærg

Research output: Contribution to journalArticle

Abstract

The γ-actin gene (ACTG1) encodes a major cytoskeletal protein of the sensory hair cells of the cochlea. Recently, mutations in ACTG1 were found to cause autosomal dominant, progressive, sensorineural hearing impairment linked to the DFNA20/26 locus on chromosome 17q25.3 in four American families and in one Dutch family. We report here the linkage of autosomal dominant, progressive, sensorineural hearing impairment in a large Norwegian family to the DFNA20/26 locus. Sequencing of ACTG1 identified a novel missense mutation (c.1109T>C; p.V370A) segregating with the hearing loss. Functional analysis in yeast showed that the p.V370A mutation restricts cell growth at elevated temperature or under hyperosmolar stress. Molecular modelling suggested that the p.V370A mutation modestly alters a site for protein-protein interaction in γ-actin and thereby modestly alters γ-actin-based cytoskeletal structures. Nineteen Norwegian and Danish families with autosomal, dominant hearing impairment were analyzed for mutations in ACTG1 by sequencing, but no disease-associated mutations were identified. Finally, a long-term follow-up of the hearing loss progression associated with the p.V370A mutation in ACTG1 is provided. The present study expands our understanding of the genotype-phenotype relationship of this deafness gene and provides a sensitive and simple functional assay for missense mutations in this gene, which may assist future molecular diagnosis of autosomal-dominant hearing impairment. Finally, the present results do not indicate that mutations in ACTG1 are a frequent cause of autosomal-dominant postlingual sensorineural hearing impairment in Norway nor Denmark.

Original languageEnglish (US)
Pages (from-to)1097-1105
Number of pages9
JournalEuropean Journal of Human Genetics
Volume14
Issue number10
DOIs
StatePublished - Oct 2006
Externally publishedYes

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Keywords

  • ACTG1
  • Deafness
  • DFNA20/26
  • Hereditary
  • Late-onset
  • Progressive

ASJC Scopus subject areas

  • Genetics(clinical)

Cite this

Rendtorff, N. D. N. D., Zhu, M., Fagerheim, T., Antal, T. L., Jones, M. P., Teslovich, T. M., Gillanders, E. M., Barmada, M., Teig, E., Trent, J. M., Friderici, K. H., Stephan, D. A., & Tranebjærg, L. (2006). A novel missense mutation in ACTG1 causes dominant deafness in a Norwegian DFNA20/26 family, but ACTG1 mutations are not frequent among families with hereditary hearing impairment. European Journal of Human Genetics, 14(10), 1097-1105. https://doi.org/10.1038/sj.ejhg.5201670