Identification of 11 novel mutations in USH2A among Japanese patients with Usher syndrome type 2

Clin Genet. 2009 Oct;76(4):383-91. doi: 10.1111/j.1399-0004.2009.01257.x. Epub 2009 Sep 8.


Usher syndrome (USH) is an autosomal recessive disorder characterized by retinitis pigmentosa and hearing loss. USH type 2 (USH2) is the most common type of USH and is frequently caused by mutations in USH2A, which accounts for 74-90% of USH2 cases. This is the first study reporting the results of scanning for USH2A mutations in Japanese patients with USH2. In 8 of 10 unrelated patients, we identified 14 different mutations. Of these mutations, 11 were novel. Although the mutation spectrum that we identified differed from that for Caucasians, the incidence of mutations in USH2A was 80% for all patients tested, which is consistent with previous findings. Further, c.8559-2A>G was identified in four patients and accounted for 26.7% of mutated alleles; it is thus a frequent mutation in Japanese patients. Hence, mutation screening for c.8559-2A>G in USH2A may prove very effective for the early diagnosis of USH2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asian People
  • DNA Mutational Analysis
  • DNA Primers / genetics
  • Extracellular Matrix Proteins / genetics*
  • Female
  • Genetic Predisposition to Disease / genetics*
  • Genetic Testing
  • Humans
  • Japan
  • Male
  • Middle Aged
  • Mutation / genetics*
  • Usher Syndromes / genetics*


  • DNA Primers
  • Extracellular Matrix Proteins
  • USH2A protein, human