Variants in CIB2 cause DFNB48 and not USH1J

K. T. Booth, K. Kahrizi, M. Babanejad, H. Daghagh, G. Bademci, S. Arzhangi, D. Zareabdollahi, D. Duman, A. El-Amraoui, M. Tekin, H. Najmabadi, H. Azaiez, R. J. Smith

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


The genetic, mutational and phenotypic spectrum of deafness-causing genes shows great diversity and pleiotropy. The best examples are the group of genes, which when mutated can either cause non-syndromic hearing loss (NSHL) or the most common dual sensory impairment, Usher syndrome (USH). Variants in the CIB2 gene have been previously reported to cause hearing loss at the DFNB48 locus and deaf-blindness at the USH1J locus. In this study, we characterize the phenotypic spectrum in a multiethnic cohort with autosomal recessive non-syndromic hearing loss (ARNSHL) due to variants in the CIB2 gene. Of the 6 families we ascertained, 3 segregated novel loss-of-function (LOF) variants, 2 families segregated missense variants (1 novel) and 1 family segregated a previously reported pathogenic variant in trans with a frameshift variant. This report is the first to show that biallelic LOF variants in CIB2 cause ARNSHL and not USH. In the era of precision medicine, providing the correct diagnosis (NSHL vs USH) is essential for patient care as it impacts potential intervention and prevention options for patients. Here, we provide evidence disqualifying CIB2 as an USH-causing gene.

Original languageEnglish (US)
Pages (from-to)812-821
Number of pages10
JournalClinical Genetics
Issue number4
StatePublished - Apr 2018


  • CIB2
  • DFNB48
  • USH1J
  • Usher syndrome
  • deafness
  • non-syndromic hearing loss

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)


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