Biology (May 2022)

<i>GJB2</i> Is a Major Cause of Non-Syndromic Hearing Impairment in Senegal

  • Yacouba Dia,
  • Samuel Mawuli Adadey,
  • Jean Pascal Demba Diop,
  • Elvis Twumasi Aboagye,
  • Seydi Abdoul Ba,
  • Carmen De Kock,
  • Cheikh Ahmed Tidjane Ly,
  • Oluwafemi Gabriel Oluwale,
  • Andrea Regina Gnilane Sène,
  • Pierre Diaga Sarr,
  • Bay Karim Diallo,
  • Rokhaya Ndiaye Diallo,
  • Ambroise Wonkam

DOI
https://doi.org/10.3390/biology11050795
Journal volume & issue
Vol. 11, no. 5
p. 795

Abstract

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This study aimed to investigate GJB2 (MIM: 121011) and GJB6 (MIM: 604418) variants associated with familial non-syndromic hearing impairment (HI) in Senegal. We investigated a total of 129 affected and 143 unaffected individuals from 44 multiplex families by segregating autosomal recessive non-syndromic HI, 9 sporadic HI cases of putative genetic origin, and 148 control individuals without personal or family history of HI. The DNA samples were screened for GJB2 coding-region variants and GJB6-D3S1830 deletions. The mean age at the medical diagnosis of the affected individuals was 2.93 ± 2.53 years [range: 1–15 years]. Consanguinity was present in 40 out of 53 families (75.47%). Variants in GJB2 explained HI in 34.1% (n = 15/44) of multiplex families. A bi-allelic pathogenic variant, GJB2: c.94C>T: p.(Arg32Cys) accounted for 25% (n = 11/44 families) of familial cases, of which 80% (n = 12/15) were consanguineous. Interestingly, the previously reported “Ghanaian” founder variant, GJB2: c.427C>T: p.(Arg143Trp), accounted for 4.5% (n = 2/44 families) of the families investigated. Among the normal controls, the allele frequency of GJB2: c.94C>T and GJB2: c.427C>T was estimated at 1% (2/148 ∗ 2) and 2% (4/148 ∗ 2), respectively. No GJB6-D3S1830 deletion was identified in any of the HI patients. This is the first report of a genetic investigation of HI in Senegal, and suggests that GJB2: c.94C>T: p.(Arg32Cys) and GJB2: c.427C>T: p.(Arg143Trp) should be tested in clinical practice for congenital HI in Senegal.

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