GJB2 Is a Major Cause of Non-Syndromic Hearing Impairment in Senegal

• Published in: Biology (Basel, Switzerland) Switzerland), 2022-05, Vol.11 (5), p.795
• Main Authors: Dia, Yacouba, Adadey, Samuel Mawuli, Diop, Jean Pascal Demba, Aboagye, Elvis Twumasi, Ba, Seydi Abdoul, De Kock, Carmen, Ly, Cheikh Ahmed Tidjane, Oluwale, Oluwafemi Gabriel, Sène, Andrea Regina Gnilane, Sarr, Pierre Diaga, Diallo, Bay Karim, Diallo, Rokhaya Ndiaye, Wonkam, Ambroise
• Format: Article
• Language: English
• Subjects: Africa; Alleles; Blood & organ donations; Consanguinity; Ethics; Etiology; Families & family life; Gene frequency; Genes; Genetics; GJB2; GJB2: c.94C>T: p.(Arg32Cys); hearing impairment; Hearing loss; Medical diagnosis; Senegal
• ISSN: 2079-7737; 2079-7737
• DOI: 10.3390/biology11050795

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.