BACKGROUND: Deafness is the most common sensory disability in the world. Globally, mutations in GJB2 (connexin 26) have been shown to play a major role in non-syndromic deafness. Two other connexin genes, GJB6 (connexin 30) and GJA1 (connexin 43), have been implicated in hearing loss, but these genes have seldom been investigated in black Africans. We aimed to validate the utility of testing for GJB2, GJB6 and GJA1 in an African context. METHODS: Two hundred and five patients with non-syndromic deafness from Cameroon and South Africa had the full coding regions of GJB2 sequenced. Subsequently, a carefully selected subset of 100 patients was further sequenced for GJB6 and GJA1 using Sanger cycle sequencing. In addition, the large-scale GJB6-D3S1830 deletion was investigated. RESULTS: No pathogenic mutations that could explain the hearing loss were detected in GJB2, GJB6 or GJA1, and the GJB6-D3S1830 deletion was not detected. There were no statistically significant differences in genomic variations in these genes between patients and controls. A comprehensive literature review supported these findings. CONCLUSION: Mutations in GJB2, GJB6 and GJA1 are not a major cause of non-syndromic deafness in black Africans and should not be investigated routinely in clinical practice.
BACKGROUND: Deafness is the most common sensory disability in the world. Globally, mutations in GJB2 (connexin 26) have been shown to play a major role in non-syndromic deafness. Two other connexin genes, GJB6 (connexin 30) and GJA1 (connexin 43), have been implicated in hearing loss, but these genes have seldom been investigated in black Africans. We aimed to validate the utility of testing for GJB2, GJB6 and GJA1 in an African context. METHODS: Two hundred and five patients with non-syndromic deafness from Cameroon and South Africa had the full coding regions of GJB2 sequenced. Subsequently, a carefully selected subset of 100 patients was further sequenced for GJB6 and GJA1 using Sanger cycle sequencing. In addition, the large-scale GJB6-D3S1830 deletion was investigated. RESULTS: No pathogenic mutations that could explain the hearing loss were detected in GJB2, GJB6 or GJA1, and the GJB6-D3S1830 deletion was not detected. There were no statistically significant differences in genomic variations in these genes between patients and controls. A comprehensive literature review supported these findings. CONCLUSION: Mutations in GJB2, GJB6 and GJA1 are not a major cause of non-syndromic deafness in black Africans and should not be investigated routinely in clinical practice.
Authors: Ambroise Wonkam; Kamogelo Lebeko; Shaheen Mowla; Jean Jacques Noubiap; Mike Chong; Guillaume Pare Journal: Mol Genet Genomic Med Date: 2021-02-02 Impact factor: 2.473
Authors: Samuel M Adadey; Kevin K Esoh; Osbourne Quaye; Geoffrey K Amedofu; Gordon A Awandare; Ambroise Wonkam Journal: Exp Biol Med (Maywood) Date: 2020-06-11
Authors: Samuel M Adadey; Edmond Tingang Wonkam; Elvis Twumasi Aboagye; Darius Quansah; Adwoa Asante-Poku; Osbourne Quaye; Geoffrey K Amedofu; Gordon A Awandare; Ambroise Wonkam Journal: Genes (Basel) Date: 2020-01-27 Impact factor: 4.141
Authors: Oluwafemi G Oluwole; Kevin K Esoh; Edmond Wonkam-Tingang; Noluthando Manyisa; Jean Jacques Noubiap; Emile R Chimusa; Ambroise Wonkam Journal: Exp Biol Med (Maywood) Date: 2020-09-30
Authors: Samuel M Adadey; Noluthando Manyisa; Khuthala Mnika; Carmen de Kock; Victoria Nembaware; Osbourne Quaye; Geoffrey K Amedofu; Gordon A Awandare; Ambroise Wonkam Journal: Front Genet Date: 2019-09-18 Impact factor: 4.599