1
|
Salame M, Bonnet C, Singh-Estivalet A, Brahim SM, Roux S, Boussaty EC, Hadrami M, Hamed CT, Sidi AM, Veten F, Petit C, Houmeida A. Splice-altering variant of PJVK gene in a Mauritanian family with non-syndromic hearing impairment. J Appl Genet 2024:10.1007/s13353-024-00903-x. [PMID: 39230647 DOI: 10.1007/s13353-024-00903-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 08/15/2024] [Accepted: 08/16/2024] [Indexed: 09/05/2024]
Abstract
PJVK gene was recently shown to create hypervulnerability to sound in humans and was the first human gene implicated in non-syndromic hearing impairment due to neural defect. Targeted next-generation sequencing of over 150 known deafness genes was performed in the proband. Sanger sequencing was used to validate the PJVK variant and confirm familial segregation of the disease. A minigene-based assay has been performed to assess the impact of the variant on splicing. We identified a novel c.550-6A > G acceptor splice-site variant in the PJVK gene in the homozygous state in a Mauritanian child with severe to profound congenital deafness. The substitution was located in intron 4. The effect of the variation was demonstrated by a minigene assay which showed that the variation, an insertion of an additional 5 bp, created a new splice site resulting in the appearance of a premature stop codon (p.Phe184Tyrfs*26) and likely a truncated protein. This result constitutes a new splice-site variant report in the PJVK gene leading to DFNB59 type associated with autosomal recessive non-syndromic hearing impairment (ARNSHI).
Collapse
Affiliation(s)
- Malak Salame
- Unité de Recherche Sur Les Biomarqueurs Dans La Population Mauritanienne, UN-FST, Nouakchott, Mauritania.
- Institut d'Hépato-Virologie, Nouakchott, Mauritania.
| | - Crystel Bonnet
- Institut de L'Audition, Institut Pasteur, Inserm, Paris, France
| | | | - Selma Mohamed Brahim
- Unité de Recherche Sur Les Biomarqueurs Dans La Population Mauritanienne, UN-FST, Nouakchott, Mauritania
- Centre National d'Oncologie (CNO), Unité de Recherche Et d'Enseignement, Nouakchott, Mauritania
| | - Solene Roux
- Institut de L'Audition, Institut Pasteur, Inserm, Paris, France
| | - Ely Cheikh Boussaty
- Division of Otolaryngology, Department of Surgery, University of California, 9500 Gilman Drive, Mail Code 0666, La Jolla, San Diego, CA, 92093, USA
| | - Mouna Hadrami
- Unité de Recherche Sur Les Biomarqueurs Dans La Population Mauritanienne, UN-FST, Nouakchott, Mauritania
| | | | - Abdellahi M'hamed Sidi
- Unité de Recherche Sur Les Biomarqueurs Dans La Population Mauritanienne, UN-FST, Nouakchott, Mauritania
| | - Fatimetou Veten
- Unité de Recherche Sur Les Biomarqueurs Dans La Population Mauritanienne, UN-FST, Nouakchott, Mauritania
| | - Christine Petit
- Institut de L'Audition, Institut Pasteur, Inserm, Paris, France
- Collège de France, Paris, France
| | - Ahmed Houmeida
- Unité de Recherche Sur Les Biomarqueurs Dans La Population Mauritanienne, UN-FST, Nouakchott, Mauritania
| |
Collapse
|
2
|
Alkhidir S, El-Akouri K, Al-Dewik N, Khodjet-El-Khil H, Okashah S, Islam N, Ben-Omran T, Al-Shafai M. The genetic basis and the diagnostic yield of genetic testing related to nonsyndromic hearing loss in Qatar. Sci Rep 2024; 14:4202. [PMID: 38378725 PMCID: PMC10879212 DOI: 10.1038/s41598-024-52784-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 01/23/2024] [Indexed: 02/22/2024] Open
Abstract
Hearing loss is the most predominant sensory defect occurring in pediatrics, of which, 66% cases are attributed to genetic factors. The prevalence of hereditary hearing loss increases in consanguineous populations, and the prevalence of hearing loss in Qatar is 5.2%. We aimed to investigate the genetic basis of nonsyndromic hearing loss (NSHL) in Qatar and to evaluate the diagnostic yield of different genetic tests available. A retrospective chart review was conducted for 59 pediatric patients with NSHL referred to the Department of Adult and Pediatric Medical Genetics at Hamad Medical Corporation in Qatar, and who underwent at least one genetic test. Out of the 59 patients, 39 were solved cases due to 19 variants in 11 genes and two copy number variants that explained the NSHL phenotype. Of them 2 cases were initially uncertain and were reclassified using familial segregation. Around 36.8% of the single variants were in GJB2 gene and c.35delG was the most common recurrent variant seen in solved cases. We detected the c.283C > T variant in FGF3 that was seen in a Qatari patient and found to be associated with NSHL for the first time. The overall diagnostic yield was 30.7%, and the diagnostic yield was significantly associated with genetic testing using GJB2 sequencing and using the hearing loss (HL) gene panel. The diagnostic yield for targeted familial testing was 60% (n = 3 patients) and for gene panel was 50% (n = 5). Thus, we recommend using GJB2 gene sequencing as a first-tier genetic test and HL gene panel as a second-tier genetic test for NSHL. Our work provided new insights into the genetic pool of NSHL among Arabs and highlights its unique diversity, this is believed to help further in the diagnostic and management options for NSHL Arab patients.
Collapse
Affiliation(s)
- Shaza Alkhidir
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
- Department of Adult and Pediatric Medical Genetics, Hamad Medical Corporation, Doha, Qatar
| | - Karen El-Akouri
- Department of Adult and Pediatric Medical Genetics, Hamad Medical Corporation, Doha, Qatar
- Division of Genetic and Genomic Medicine, Sidra Medicine, Doha, Qatar
| | - Nader Al-Dewik
- Department of Adult and Pediatric Medical Genetics, Hamad Medical Corporation, Doha, Qatar
| | - Houssein Khodjet-El-Khil
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
| | - Sarah Okashah
- Department of Adult and Pediatric Medical Genetics, Hamad Medical Corporation, Doha, Qatar
- Department of Public Health, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
| | - Nazmul Islam
- Department of Public Health, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
- Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada
| | - Tawfeg Ben-Omran
- Department of Adult and Pediatric Medical Genetics, Hamad Medical Corporation, Doha, Qatar.
- Division of Genetic and Genomic Medicine, Sidra Medicine, Doha, Qatar.
| | - Mashael Al-Shafai
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, Doha, Qatar.
- Biomedical Research Center, Qatar University, Doha, Qatar.
| |
Collapse
|
3
|
Salame M, Bonnet C, Moctar ECM, Brahim SM, Dedy A, Vetah LA, Veten F, Hamed CT, Petit C, Houmeida A. Identification a novel pathogenic LRTOMT mutation in Mauritanian families with nonsyndromic deafness. Eur Arch Otorhinolaryngol 2023; 280:4057-4063. [PMID: 36928321 DOI: 10.1007/s00405-023-07907-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 02/27/2023] [Indexed: 03/18/2023]
Abstract
PURPOSE Although recessive mutations in GJB2 are the common genetic etiology of sensorineural hearing impairment (SNHI), variants in LRTOMT gene were also identified, mostly in Middle East and North African populations. METHODS Using Sanger sequencing we screened the exon 7 of LRTOMT in a cohort of 128 unrelated Mauritanian children with congenital deafness. RESULTS Only one biallelic missense mutation, predicted as pathogenic (c.179 T > C;p.Leu60Pro) was found at homozygous state in four families. This variant, not reported before, showed a deleterious effect by SIFT (score: 0.01) and a disease-causing effect by Mutation Taster (prob: 1). Exploration of the encoded protein 3D structure revealed a disruption from an organized α helix (in the normal protein structure) into a random conformation. Early fitting of a cochlear implant seemed to improve the audition ability of the mutation carrier. CONCLUSION Further screening using a panel of deafness genes may expose other variants underlying hearing impairment in our population.
Collapse
Affiliation(s)
- Malak Salame
- Unité de Recherche sur les Biomarqueurs dans la Population Mauritanienne, UNA-FST, Nouakchott, Mauritania
| | - Crystel Bonnet
- Institut de l'AuditionInstitut Pasteur, Inserm, Paris, France
| | - Ely Cheikh Mohamed Moctar
- Division of Otolaryngology, Department of Surgery, University of California, San Diego, 9500 Gilman Drive, Mail Code 0666, La Jolla, CA, 92093, USA
| | - Selma Mohamed Brahim
- Unité de Recherche sur les Biomarqueurs dans la Population Mauritanienne, UNA-FST, Nouakchott, Mauritania
- Centre National d'Oncologie (CNO), Unité de Recherche et d'Enseignement, Nouakchott, Mauritania
| | - Abdallahi Dedy
- Centre Hospitalier National de Nouakchott (CHN), Nouakchott, Mauritania
| | | | - Fatimetou Veten
- Unité de Recherche sur les Biomarqueurs dans la Population Mauritanienne, UNA-FST, Nouakchott, Mauritania
| | | | - Christine Petit
- Institut de l'AuditionInstitut Pasteur, Inserm, Paris, France
- Collège de France, Paris, France
| | - Ahmed Houmeida
- Unité de Recherche sur les Biomarqueurs dans la Population Mauritanienne, UNA-FST, Nouakchott, Mauritania.
| |
Collapse
|
4
|
Dia Y, Adadey SM, Diop JPD, Aboagye ET, Ba SA, De Kock C, Ly CAT, Oluwale OG, Sène ARG, Sarr PD, Diallo BK, Diallo RN, Wonkam A. GJB2 Is a Major Cause of Non-Syndromic Hearing Impairment in Senegal. BIOLOGY 2022; 11:795. [PMID: 35625523 PMCID: PMC9138795 DOI: 10.3390/biology11050795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 11/29/2022]
Abstract
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.
Collapse
Affiliation(s)
- Yacouba Dia
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Samuel Mawuli Adadey
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Legon, Accra P.O. Box LG 54, Ghana
| | - Jean Pascal Demba Diop
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Elvis Twumasi Aboagye
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
| | - Seydi Abdoul Ba
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Carmen De Kock
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
| | - Cheikh Ahmed Tidjane Ly
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Oluwafemi Gabriel Oluwale
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
| | - Andrea Regina Gnilane Sène
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Pierre Diaga Sarr
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Bay Karim Diallo
- Department of Oto-Rhino-Laryngology, Albert Royer Children’s Hospital, Dakar 10700, Senegal;
| | - Rokhaya Ndiaye Diallo
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Ambroise Wonkam
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
- McKusick-Nathans Institute and Department of Genetic Medicine, Johns-Hopskins University School of Medicine, Baltimore, MD 21205, USA
| |
Collapse
|
5
|
Wonkam-Tingang E, Kengne Kamga K, Adadey SM, Nguefack S, De Kock C, Munung NS, Wonkam A. Knowledge and Challenges Associated With Hearing Impairment in Affected Individuals From Cameroon (Sub-Saharan Africa). FRONTIERS IN REHABILITATION SCIENCES 2021; 2:726761. [PMID: 36188771 PMCID: PMC9397862 DOI: 10.3389/fresc.2021.726761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/22/2021] [Indexed: 11/13/2022]
Abstract
Background: This study aimed to gain an understanding of the challenges faced by people with hearing impairment (HI) in Cameroon, their understanding of the causes of HI, and how challenges could be remedied to improve the quality of life of persons with HI. Methods: Semi-structured one-on-one in-depth interviews and observation of participant behaviour when answering questions were used to collect data from 10 HI professionals (healthcare workers and educationists), and 10 persons affected by HI (including caregivers). Results: The results show that the different groups associate the causes of HI to genetics, environmental factors, and a spiritual curse. There were reported cases of stigma and discrimination of persons with HI, with people sometimes referring to HI as an “intellectual disorder.” Interviewees also highlighted the difficulty persons with HI have in accessing education and healthcare services and suggested the need for the government and health researchers to develop strategies for the prevention and early diagnosis of HI. These strategies include (1) the awareness of the general population regarding HI, (2) the development of facilities for the proper management and new-born screening of HI, and (3) the implementation of a premarital screening to reduce the burden of HI of genetic origin. Conclusions: This study confirms the difficult social interaction and access to proper management faced by persons with HI in Cameroon and further highlights the need to educate populations on the causes of HI for a better acceptance of individuals with HI in the Cameroonian society.
Collapse
Affiliation(s)
- Edmond Wonkam-Tingang
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Karen Kengne Kamga
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Samuel Mawuli Adadey
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Seraphin Nguefack
- Department of Paediatrics, University of Yaounde 1, Yaounde, Cameroon
| | - Carmen De Kock
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Nchangwi Syntia Munung
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Ambroise Wonkam
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- *Correspondence: Ambroise Wonkam
| |
Collapse
|
6
|
Souissi A, Gibriel AA, Masmoudi S. Genetics and meta-analysis of recessive non-syndromic hearing impairment and Usher syndrome in Maghreb population: lessons from the past, contemporary actualities and future challenges. Hum Genet 2021; 141:583-593. [PMID: 34268600 DOI: 10.1007/s00439-021-02314-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/08/2021] [Indexed: 11/29/2022]
Abstract
Hereditary hearing impairment (HI) is a heterogeneous condition with over 130 genes associated with genetic non-syndromic HI (NSHI) and Usher syndrome (USH). Approximately 80% of hereditary NSHI cases have autosomal recessive (AR) mode of inheritance. The high rate of consanguinity and endogamy in the Maghreb countries, including Tunisia, Algeria and Morocco, represents a major contributing factor to the development of ARHI. Since the 90s, those populations, with their particular large familiar structure, represented an effective key towards the discovery of the first HI loci and genes. In this study, we performed a deep literature database search to analyze the mutational spectrum and the distribution of pathogenic variants responsible of USH and the NSHI among those populations. To date, 124 pathogenic variants were identified in 32 genes of which over 70% represent population-specific variants. The particular variants' distribution is related to the high rate of consanguinity as well as the multiple shared features such as demographic history of migrations and social behavior that promoted the spreading of several founder mutations within those countries. This is the first study to report lessons from the past and current actualities of HI within the three Maghreb countries. However, despite the great impact placed by such population for the HI genetic studies, only a few next-generation sequencing platforms have so far been implemented with those countries. We, therefore, believe that those countries should be supported to implement this technology that would definitely be of great value in the discovery of additional novel HI genes/variants.
Collapse
Affiliation(s)
- Amal Souissi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Sidi Mansour road Km 6, BP "1177", 3018, Sfax, Tunisia
| | - Abdullah A Gibriel
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Sidi Mansour road Km 6, BP "1177", 3018, Sfax, Tunisia.
| |
Collapse
|
7
|
Moussaoui A, El Qabli M, Adarmouch L, Aboussair N. The frequency of the homozygote 35delG mutation in the connexin 26 gene in North African with non-syndromic hearing loss: A meta-analysis study. Meta Gene 2021. [DOI: 10.1016/j.mgene.2021.100895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
8
|
Abstract
BACKGROUND Hearing loss (HL) is a heterogeneous condition that causes partial or complete hearing impairment. Hundreds of variants in more than 60 genes have been reported to be associated with Hereditary HL (HHL). The HHL prevalence is thought to be high in the Arab population; however, the genetic epidemiology of HHL among Arab populations is understudied. This study aimed to systematically analyze the genetic epidemiology of HHL in Arab countries. METHODS We searched four literature databases (PubMed, Scopus, Science Direct, and Web of Science) from the time of inception until January 2019 using broad search terms to capture all the reported epidemiological and genetic data related to Arab patients with HHL. FINDINGS A total of 2,600 citations were obtained; 96 studies met our inclusion criteria. Our search strategy yielded 121,276 individuals who were tested for HL over 52 years (1966-2018), of whom 8,099 were clinically diagnosed with HL and belonged to 16 Arab countries. A total of 5,394 patients and 61 families with HHL were genotyped, of whom 336 patients and 6 families carried 104 variants in 44 genes and were from 17/22 Arab countries. Of these variants, 72 (in 41 genes) were distinctive to Arab patients. Arab patients manifested distinctive clinical phenotypes. The incidence of HHL in the captured studies ranged from 1.20 to 18 per 1,000 births per year, and the prevalence was the highest in Iraq (76.3%) and the lowest in Jordan (1.5%). INTERPRETATION This is the first systematic review to capture the prevalence and spectrum of variants associated with HHL in an Arab population. There appears to be a distinctive clinical picture for Arab patients with HHL, and the range and distribution of variants among Arab patients differ from those noted in other affected ethnic groups.
Collapse
|
9
|
Yalcouyé A, Traoré O, Taméga A, Maïga AB, Kané F, Oluwole OG, Guinto CO, Kéita M, Timbo SK, DeKock C, Landouré G, Wonkam A. Etiologies of Childhood Hearing Impairment in Schools for the Deaf in Mali. Front Pediatr 2021; 9:726776. [PMID: 34912757 PMCID: PMC8667071 DOI: 10.3389/fped.2021.726776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/01/2021] [Indexed: 11/13/2022] Open
Abstract
Objectives: To identify the etiologies of hearing impairment (HI) in schools for students who are deaf and to use a systematic review to summarize reports on the etiologies and clinical and genetic features of HI in Mali. Methods: We included individuals with HI that started before the age of 15 years old. Patients were carefully evaluated under standard practices, and pure-tone audiometry was performed where possible. We then searched for articles published on HI in the Malian population from the databases' inception to March 30, 2020. Results: A total of 117 individuals from two schools for the deaf were included, and a male predominance (sex ratio 1.3; 65/52) was noted. HI was pre-lingual in 82.2% (n = 117), and the median age at diagnosis was 12 years old. The etiologies were environmental in 59.4% (70/117), with meningitis being the leading cause (40%, 20/70), followed by cases with genetic suspicion (29.3%, 21/117). In 11.3% (8/117) of patients, no etiology was identified. Among cases with genetic suspicion, three were syndromic, including two cases of Waardenburg syndrome, while 15 individuals had non-syndromic HI. An autosomal recessive inheritance pattern was observed in 83.3% of families (15/18), and consanguinity was reported in 55.5% (10/18) of putative genetic cases. Conclusion: This study concludes that environmental factors are the leading causes of HI in Mali. However, genetic causes should be investigated, particularly in the context of a population with a high consanguinity rate.
Collapse
Affiliation(s)
- Abdoulaye Yalcouyé
- Faculté de Médecine et d'Odondostomatologie, Université des Sciences, Techniques et Technologies de Bamako (USTTB), Bamako, Mali.,Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Oumou Traoré
- Faculté de Médecine et d'Odondostomatologie, Université des Sciences, Techniques et Technologies de Bamako (USTTB), Bamako, Mali
| | - Abdoulaye Taméga
- Faculté de Médecine et d'Odondostomatologie, Université des Sciences, Techniques et Technologies de Bamako (USTTB), Bamako, Mali
| | - Alassane B Maïga
- Faculté de Médecine et d'Odondostomatologie, Université des Sciences, Techniques et Technologies de Bamako (USTTB), Bamako, Mali
| | - Fousseyni Kané
- Faculté de Médecine et d'Odondostomatologie, Université des Sciences, Techniques et Technologies de Bamako (USTTB), Bamako, Mali
| | - Oluwafemi G Oluwole
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Cheick Oumar Guinto
- Faculté de Médecine et d'Odondostomatologie, Université des Sciences, Techniques et Technologies de Bamako (USTTB), Bamako, Mali.,Service de Neurologie, Centre Hospitalier Universitaire du Point "G", Bamako, Mali
| | - Mohamed Kéita
- Faculté de Médecine et d'Odondostomatologie, Université des Sciences, Techniques et Technologies de Bamako (USTTB), Bamako, Mali.,Service d'ORL, Centre Hospitalier Universitaire de Gabriel Touré, Bamako, Mali
| | - Samba Karim Timbo
- Faculté de Médecine et d'Odondostomatologie, Université des Sciences, Techniques et Technologies de Bamako (USTTB), Bamako, Mali.,Service d'ORL, Centre Hospitalier Universitaire de Gabriel Touré, Bamako, Mali
| | - Carmen DeKock
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Guida Landouré
- Faculté de Médecine et d'Odondostomatologie, Université des Sciences, Techniques et Technologies de Bamako (USTTB), Bamako, Mali.,Service de Neurologie, Centre Hospitalier Universitaire du Point "G", Bamako, Mali
| | - Ambroise Wonkam
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town, South Africa.,Department of Medicine, University of Cape Town, Cape Town, South Africa
| |
Collapse
|
10
|
Adadey SM, Wonkam-Tingang E, Twumasi Aboagye E, Nayo-Gyan DW, Boatemaa Ansong M, Quaye O, Awandare GA, Wonkam A. Connexin Genes Variants Associated with Non-Syndromic Hearing Impairment: A Systematic Review of the Global Burden. Life (Basel) 2020; 10:life10110258. [PMID: 33126609 PMCID: PMC7693846 DOI: 10.3390/life10110258] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/18/2020] [Accepted: 10/27/2020] [Indexed: 12/21/2022] Open
Abstract
Mutations in connexins are the most common causes of hearing impairment (HI) in many populations. Our aim was to review the global burden of pathogenic and likely pathogenic (PLP) variants in connexin genes associated with HI. We conducted a systematic review of the literature based on targeted inclusion/exclusion criteria of publications from 1997 to 2020. The databases used were PubMed, Scopus, Africa-Wide Information, and Web of Science. The protocol was registered on PROSPERO, the International Prospective Register of Systematic Reviews, with the registration number “CRD42020169697”. The data extracted were analyzed using Microsoft Excel and SPSS version 25 (IBM, Armonk, New York, United States). A total of 571 independent studies were retrieved and considered for data extraction with the majority of studies (47.8% (n = 289)) done in Asia. Targeted sequencing was found to be the most common technique used in investigating connexin gene mutations. We identified seven connexin genes that were associated with HI, and GJB2 (520/571 publications) was the most studied among the seven. Excluding PLP in GJB2, GJB6, and GJA1 the other connexin gene variants (thus GJB3, GJB4, GJC3, and GJC1 variants) had conflicting association with HI. Biallelic GJB2 PLP variants were the most common and widespread variants associated with non-syndromic hearing impairment (NSHI) in different global populations but absent in most African populations. The most common GJB2 alleles found to be predominant in specific populations include; p.Gly12ValfsTer2 in Europeans, North Africans, Brazilians, and Americans; p.V37I and p.L79Cfs in Asians; p.W24X in Indians; p.L56Rfs in Americans; and the founder mutation p.R143W in Africans from Ghana, or with putative Ghanaian ancestry. The present review suggests that only GJB2 and GJB3 are recognized and validated HI genes. The findings call for an extensive investigation of the other connexin genes in many populations to elucidate their contributions to HI, in order to improve gene-disease pair curations, globally.
Collapse
Affiliation(s)
- Samuel Mawuli Adadey
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, P.O. Box LG 54, Legon GA184, Accra, Greater Accra Region, Ghana; (S.M.A.); (O.Q.); (G.A.A.)
- Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P.O. Box LG 54, Legon Accra GA184, Greater Accra Region, Ghana; (E.T.A.); (M.B.A.)
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town 7925, South Africa;
| | - Edmond Wonkam-Tingang
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town 7925, South Africa;
| | - Elvis Twumasi Aboagye
- Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P.O. Box LG 54, Legon Accra GA184, Greater Accra Region, Ghana; (E.T.A.); (M.B.A.)
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town 7925, South Africa;
| | - Daniel Wonder Nayo-Gyan
- Department of Applied Chemistry and Biochemistry, C. K. Tedam University of Technology and Applied Sciences, P.O. Box 24, Navrongo 00000, Upper East Region, Ghana;
| | - Maame Boatemaa Ansong
- Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P.O. Box LG 54, Legon Accra GA184, Greater Accra Region, Ghana; (E.T.A.); (M.B.A.)
| | - Osbourne Quaye
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, P.O. Box LG 54, Legon GA184, Accra, Greater Accra Region, Ghana; (S.M.A.); (O.Q.); (G.A.A.)
- Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P.O. Box LG 54, Legon Accra GA184, Greater Accra Region, Ghana; (E.T.A.); (M.B.A.)
| | - Gordon A. Awandare
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, P.O. Box LG 54, Legon GA184, Accra, Greater Accra Region, Ghana; (S.M.A.); (O.Q.); (G.A.A.)
- Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P.O. Box LG 54, Legon Accra GA184, Greater Accra Region, Ghana; (E.T.A.); (M.B.A.)
| | - Ambroise Wonkam
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town 7925, South Africa;
- Correspondence: ; Tel.: +27-21-4066307
| |
Collapse
|
11
|
Abstract
The incidence of hearing impairment (HI) is higher in low- and middle-income countries when compared to high-income countries. There is therefore a necessity to estimate the burden of this condition in developing world. The aim of our study was to use a systematic approach to provide summarized data on the prevalence, etiologies, clinical patterns and genetics of HI in Cameroon. We searched PubMed, Scopus, African Journals Online, AFROLIB and African Index Medicus to identify relevant studies on HI in Cameroon, published from inception to 31 October, 2019, with no language restrictions. Reference lists of included studies were also scrutinized, and data were summarized narratively. This study is registered with PROSPERO, number CRD42019142788. We screened 333 records, of which 17 studies were finally included in the review. The prevalence of HI in Cameroon ranges from 0.9% to 3.6% in population-based studies and increases with age. Environmental factors contribute to 52.6% to 62.2% of HI cases, with meningitis, impacted wax and age-related disorder being the most common ones. Hereditary HI comprises 0.8% to 14.8% of all cases. In 32.6% to 37% of HI cases, the origin remains unknown. Non-syndromic hearing impairment (NSHI) is the most frequent clinical entity and accounts for 86.1% to 92.5% of cases of HI of genetic origin. Waardenburg and Usher syndromes account for 50% to 57.14% and 8.9% to 42.9% of genetic syndromic cases, respectively. No pathogenic mutation was described in GJB6 gene, and the prevalence of pathogenic mutations in GJB2 gene ranged from 0% to 0.5%. The prevalence of pathogenic mutations in other known NSHI genes was <10% in Cameroonian probands. Environmental factors are the leading etiology of HI in Cameroon, and mutations in most important HI genes are infrequent in Cameroon. Whole genome sequencing therefore appears as the most effective way to identify variants associated with HI in Cameroon and sub-Saharan Africa in general.
Collapse
|
12
|
Wonkam Tingang E, Noubiap JJ, F. Fokouo JV, Oluwole OG, Nguefack S, Chimusa ER, Wonkam A. Hearing Impairment Overview in Africa: the Case of Cameroon. Genes (Basel) 2020; 11:genes11020233. [PMID: 32098311 PMCID: PMC7073999 DOI: 10.3390/genes11020233] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 02/15/2020] [Accepted: 02/19/2020] [Indexed: 01/27/2023] Open
Abstract
The incidence of hearing impairment (HI) is higher in low- and middle-income countries when compared to high-income countries. There is therefore a necessity to estimate the burden of this condition in developing world. The aim of our study was to use a systematic approach to provide summarized data on the prevalence, etiologies, clinical patterns and genetics of HI in Cameroon. We searched PubMed, Scopus, African Journals Online, AFROLIB and African Index Medicus to identify relevant studies on HI in Cameroon, published from inception to 31 October, 2019, with no language restrictions. Reference lists of included studies were also scrutinized, and data were summarized narratively. This study is registered with PROSPERO, number CRD42019142788. We screened 333 records, of which 17 studies were finally included in the review. The prevalence of HI in Cameroon ranges from 0.9% to 3.6% in population-based studies and increases with age. Environmental factors contribute to 52.6% to 62.2% of HI cases, with meningitis, impacted wax and age-related disorder being the most common ones. Hereditary HI comprises 0.8% to 14.8% of all cases. In 32.6% to 37% of HI cases, the origin remains unknown. Non-syndromic hearing impairment (NSHI) is the most frequent clinical entity and accounts for 86.1% to 92.5% of cases of HI of genetic origin. Waardenburg and Usher syndromes account for 50% to 57.14% and 8.9% to 42.9% of genetic syndromic cases, respectively. No pathogenic mutation was described in GJB6 gene, and the prevalence of pathogenic mutations in GJB2 gene ranged from 0% to 0.5%. The prevalence of pathogenic mutations in other known NSHI genes was <10% in Cameroonian probands. Environmental factors are the leading etiology of HI in Cameroon, and mutations in most important HI genes are infrequent in Cameroon. Whole genome sequencing therefore appears as the most effective way to identify variants associated with HI in Cameroon and sub-Saharan Africa in general.
Collapse
Affiliation(s)
- Edmond Wonkam Tingang
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town 7925, South Africa; (E.W.T.); (O.G.O.); (E.R.C.)
| | - Jean Jacques Noubiap
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide 5000, Australia;
| | | | - Oluwafemi Gabriel Oluwole
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town 7925, South Africa; (E.W.T.); (O.G.O.); (E.R.C.)
| | - Séraphin Nguefack
- Department of Paediatrics, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé 1364, Cameroon;
- Paediatrics unit, Gynaeco-Obstetric and Paediatric Hospital, Yaoundé 4362, Cameroon
| | - Emile R. Chimusa
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town 7925, South Africa; (E.W.T.); (O.G.O.); (E.R.C.)
| | - Ambroise Wonkam
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town 7925, South Africa; (E.W.T.); (O.G.O.); (E.R.C.)
- Department of Medicine, University of Cape Town, Cape Town 7925, South Africa
- Correspondence: ; Tel.: +27-21-4066-307
| |
Collapse
|
13
|
Mittal R, Patel AP, Nguyen D, Pan DR, Jhaveri VM, Rudman JR, Dharmaraja A, Yan D, Feng Y, Chapagain P, Lee DJ, Blanton SH, Liu XZ. Genetic basis of hearing loss in Spanish, Hispanic and Latino populations. Gene 2018; 647:297-305. [PMID: 29331482 PMCID: PMC5806531 DOI: 10.1016/j.gene.2018.01.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/02/2018] [Accepted: 01/06/2018] [Indexed: 12/13/2022]
Abstract
Hearing loss (HL) is the most common neurosensory disorder affecting humans. The screening, prevention and treatment of HL require a better understanding of the underlying molecular mechanisms. Genetic predisposition is one of the most common factors that leads to HL. Most HL studies include few Spanish, Hispanic and Latino participants, leaving a critical gap in our understanding about the prevalence, impact, unmet health care needs, and genetic factors associated with hearing impairment among Spanish, Hispanic and Latino populations. The few studies which have been performed show that the gene variants commonly associated with HL in non-Spanish and non-Hispanic populations are infrequently responsible for hearing impairment in Spanish as well as Hispanic and Latino populations (hereafter referred to as Hispanic). To design effective screening tools to detect HL in Spanish and Hispanic populations, studies must be conducted to determine the gene variants that are most commonly associated with hearing impairment in this racial/ethnic group. In this review article, we summarize gene variants and loci associated with HL in Spanish and Hispanic populations. Identifying new genetic variants associated with HL in Spanish and Hispanic populations will pave the way to develop effective screening tools and therapeutic strategies for HL.
Collapse
Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Amit P Patel
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Desiree Nguyen
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Debbie R Pan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Vasanti M Jhaveri
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jason R Rudman
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Arjuna Dharmaraja
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Yong Feng
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China
| | - Prem Chapagain
- Department of Physics and Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - David J Lee
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Susan H Blanton
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA; Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China; Tsinghua University School of Medicine, Beijing 10084, China; Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| |
Collapse
|
14
|
Mittal R, Nguyen D, Patel AP, Debs LH, Mittal J, Yan D, Eshraghi AA, Van De Water TR, Liu XZ. Recent Advancements in the Regeneration of Auditory Hair Cells and Hearing Restoration. Front Mol Neurosci 2017; 10:236. [PMID: 28824370 PMCID: PMC5534485 DOI: 10.3389/fnmol.2017.00236] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/11/2017] [Indexed: 12/18/2022] Open
Abstract
Neurosensory responses of hearing and balance are mediated by receptors in specialized neuroepithelial sensory cells. Any disruption of the biochemical and molecular pathways that facilitate these responses can result in severe deficits, including hearing loss and vestibular dysfunction. Hearing is affected by both environmental and genetic factors, with impairment of auditory function being the most common neurosensory disorder affecting 1 in 500 newborns, as well as having an impact on the majority of elderly population. Damage to auditory sensory cells is not reversible, and if sufficient damage and cell death have taken place, the resultant deficit may lead to permanent deafness. Cochlear implants are considered to be one of the most successful and consistent treatments for deaf patients, but only offer limited recovery at the expense of loss of residual hearing. Recently there has been an increased interest in the auditory research community to explore the regeneration of mammalian auditory hair cells and restoration of their function. In this review article, we examine a variety of recent therapies, including genetic, stem cell and molecular therapies as well as discussing progress being made in genome editing strategies as applied to the restoration of hearing function.
Collapse
Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Desiree Nguyen
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Amit P. Patel
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Luca H. Debs
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Jeenu Mittal
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Adrien A. Eshraghi
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Thomas R. Van De Water
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Xue Z. Liu
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
- Department of Otolaryngology, Xiangya Hospital, Central South UniversityChangsha, China
| |
Collapse
|