Molecular and genetic characterization of a large Brazilian cohort presenting hearing loss
| Autor: | Diego Mariano, Cindy Yukimi Sonoda, Juliana Sampaio-Silva, Osório Abath-Neto, Vinicius Pedroso-Campos, Estefany Uchoa da Silva de Oliveira Longati, Karina Lezirovitz, Ana Carla Batissoco, Ricardo Ferreira Bento, Rafaela Jesus-Santos, Jeanne Oiticica, Ana Cristina Hiromi Hoshino, Gleiciele Alice Vieira-Silva, Robinson Koji Tsuji, Eliete Pardono |
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| Rok vydání: | 2021 |
| Předmět: |
Proband
Pediatrics medicine.medical_specialty Hearing loss Auditory neuropathy Population Connexins Cohort Studies Genetics medicine Humans Genetic Testing Hearing Loss education Genetics (clinical) education.field_of_study biology Waardenburg syndrome Genetic heterogeneity medicine.disease Human genetics Connexin 26 Mutation biology.protein medicine.symptom Brazil GJB6 |
| Zdroj: | Human Genetics. 141:519-538 |
| ISSN: | 1432-1203 0340-6717 |
| Popis: | Hearing loss is one of the most common sensory defects, affecting 5.5% of the worldwide population and significantly impacting health and social life. It is mainly attributed to genetic causes, but their relative contribution reflects the geographical region’s socio-economic development. Extreme genetic heterogeneity with hundreds of deafness genes involved poses challenges for molecular diagnosis. Here we report the investigation of 542 hearing-impaired subjects from all Brazilian regions to search for genetic causes. Biallelic GJB2/GJB6 causative variants were identified in 12.9% (the lowest frequency was found in the Northern region, 7.7%), 0.4% carried GJB2 dominant variants, and 0.6% had the m.1555A > G variant (one aminoglycoside-related). In addition, other genetic screenings, employed in selected probands according to clinical presentation and presumptive inheritance patterns, identified causative variants in 2.4%. Ear malformations and auditory neuropathy were diagnosed in 10.8% and 3.5% of probands, respectively. In 3.8% of prelingual/perilingual cases, Waardenburg syndrome was clinically diagnosed, and in 71.4%, these diagnoses were confirmed with pathogenic variants revealed; seven out of them were novel, including one CNV. All these genetic screening strategies revealed causative variants in 16.2% of the cases. Based on causative variants in the molecular diagnosis and genealogy analyses, a probable genetic etiology was found in ~ 50% of the cases. The present study highlights the relevance of GJB2/GJB6 as a cause of hearing loss in all Brazilian regions and the importance of screening unselected samples for estimating frequencies. Moreover, when a comprehensive screening is not available, molecular diagnosis can be enhanced by selecting probands for specific screenings. |
| Databáze: | OpenAIRE |
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