PUBLICATION

A biallelic variant in CLRN2 causes non-syndromic hearing loss in humans

Authors
Vona, B., Mazaheri, N., Lin, S.J., Dunbar, L.A., Maroofian, R., Azaiez, H., Booth, K.T., Vitry, S., Rad, A., Rüschendorf, F., Varshney, P., Fowler, B., Beetz, C., Alagramam, K.N., Murphy, D., Shariati, G., Sedaghat, A., Houlden, H., Petree, C., VijayKumar, S., Smith, R.J.H., Haaf, T., El-Amraoui, A., Bowl, M.R., Varshney, G.K., Galehdari, H.
ID
ZDB-PUB-210128-7
Date
2021
Source
Human genetics   140(6): 915-931 (Journal)
Registered Authors
Alagramam, Kumar N., Lin, Sheng-Jia, Varshney, Gaurav
Keywords
none
MeSH Terms
  • Adult
  • Alleles
  • Amino Acid Substitution*
  • Animals
  • Base Sequence
  • Chromosome Mapping
  • Chromosomes, Human, Pair 4/chemistry*
  • Consanguinity
  • Exome Sequencing
  • Female
  • Gene Expression
  • Genes, Recessive
  • Hair Cells, Auditory, Inner/metabolism*
  • Hair Cells, Auditory, Inner/pathology
  • Hearing Loss, Sensorineural/genetics*
  • Hearing Loss, Sensorineural/metabolism
  • Hearing Loss, Sensorineural/pathology
  • Humans
  • Male
  • Membrane Proteins/deficiency
  • Membrane Proteins/genetics*
  • Mice
  • Pedigree
  • Point Mutation*
  • Tetraspanins/deficiency
  • Tetraspanins/genetics*
  • Zebrafish
PubMed
33496845 Full text @ Hum. Genet.
Abstract
Deafness, the most frequent sensory deficit in humans, is extremely heterogeneous with hundreds of genes involved. Clinical and genetic analyses of an extended consanguineous family with pre-lingual, moderate-to-profound autosomal recessive sensorineural hearing loss, allowed us to identify CLRN2, encoding a tetraspan protein, as a new deafness gene. Homozygosity mapping followed by exome sequencing identified a 14.96 Mb locus on chromosome 4p15.32p15.1 containing a likely pathogenic missense variant in CLRN2 (c.494C > A, NM_001079827.2) segregating with the disease. Using in vitro RNA splicing analysis, we show that the CLRN2 c.494C > A variant leads to two events: (1) the substitution of a highly conserved threonine (uncharged amino acid) to lysine (charged amino acid) at position 165, p.(Thr165Lys), and (2) aberrant splicing, with the retention of intron 2 resulting in a stop codon after 26 additional amino acids, p.(Gly146Lysfs*26). Expression studies and phenotyping of newly produced zebrafish and mouse models deficient for clarin 2 further confirm that clarin 2, expressed in the inner ear hair cells, is essential for normal organization and maintenance of the auditory hair bundles, and for hearing function. Together, our findings identify CLRN2 as a new deafness gene, which will impact future diagnosis and treatment for deaf patients.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping