OBJECTIVES/HYPOTHESIS: Congenital deafness occurs in approximately 1 in 1,000 live births, and 50% of these cases are hereditary. Connexin mutations have been identified as the most common cause of hereditary hearing loss in many populations. The prevalence of this mutation in African patients has not been adequately studied. The objective of this study was to determine the prevalence of connexin 26 and 30 mutations in a population of hearing-impaired patients from Uganda. STUDY DESIGN: This is an observational study. METHODS: Coding regions of both GJB2 and GJB6, noncoding exon 1 of GJB2, and 30 nucleotides of intronic sequence bordering the exons were analyzed in 126 subjects from Uganda with confirmed bilateral, severe-to-profound sensorineural hearing loss. All variants were analyzed for possible clinical significance using a combination of database searches and in silico tools. RESULTS: Complete sequence data were obtained on 115/126 individuals; 11 had only partial or no results. Only one reported pathogenic variant was found in GJB2 (c.208C>G; p.Pro70Ala) and none in GJB6. Three reported variants and two novel variants within intron 1 of GJB2 and two variants within exon 3 of GJB6 were also found. CONCLUSIONS: None of the most common types of deletions in the GJB2 gene (c.35delG, c.167delT or c.235delC) were found in this large cohort of deaf children from Uganda. This prompts a search for genetic causes of deafness among this and other previously studied African populations.
OBJECTIVES/HYPOTHESIS: Congenital deafness occurs in approximately 1 in 1,000 live births, and 50% of these cases are hereditary. Connexin mutations have been identified as the most common cause of hereditary hearing loss in many populations. The prevalence of this mutation in African patients has not been adequately studied. The objective of this study was to determine the prevalence of connexin 26 and 30 mutations in a population of hearing-impairedpatients from Uganda. STUDY DESIGN: This is an observational study. METHODS: Coding regions of both GJB2 and GJB6, noncoding exon 1 of GJB2, and 30 nucleotides of intronic sequence bordering the exons were analyzed in 126 subjects from Uganda with confirmed bilateral, severe-to-profound sensorineural hearing loss. All variants were analyzed for possible clinical significance using a combination of database searches and in silico tools. RESULTS: Complete sequence data were obtained on 115/126 individuals; 11 had only partial or no results. Only one reported pathogenic variant was found in GJB2 (c.208C>G; p.Pro70Ala) and none in GJB6. Three reported variants and two novel variants within intron 1 of GJB2 and two variants within exon 3 of GJB6 were also found. CONCLUSIONS: None of the most common types of deletions in the GJB2 gene (c.35delG, c.167delT or c.235delC) were found in this large cohort of deaf children from Uganda. This prompts a search for genetic causes of deafness among this and other previously studied African populations.
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; 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
Authors: Edmond Wonkam Tingang; Jean Jacques Noubiap; Jean Valentin F Fokouo; Oluwafemi Gabriel Oluwole; Séraphin Nguefack; Emile R Chimusa; Ambroise Wonkam Journal: Genes (Basel) Date: 2020-02-22 Impact factor: 4.141
Authors: Samuel Mawuli Adadey; Edmond Wonkam-Tingang; Elvis Twumasi Aboagye; Daniel Wonder Nayo-Gyan; Maame Boatemaa Ansong; Osbourne Quaye; Gordon A Awandare; Ambroise Wonkam Journal: Life (Basel) Date: 2020-10-28