Spectrum of DNA Variants Underlying Deafness in an Ecuadorian Cohort

The genetic etiology of hearing loss (HL) in Ecuador remains largely unexplored. This study investigates the spectrum of genetic variants associated with HL in a cohort of 66 Ecuadorian families using Exome or Genome sequencing (ES/GS). We identified pathogenic and likely pathogenic variants underlying HL in 27 families (41%). While variants were detected in 15 different genes, only GJB2 (in 12 families) and TMC1 (in 3 families) variants were identified in more than one family. The NM_004004.6 (GJB2):c.19 C > T (p.Gln7*) and NM_004004.6 (GJB2):c.35delG (p.Gly12Valfs*2) variants were more common than other alleles in GJB2. In some families, we detected variants of uncertain significance (VUS) in well-established HL genes and classified them as "possibly solved" due to their rarity and equivocal functional predictions. This study provides valuable insights into the genetic basis of HL in Ecuador and lays the groundwork for improved regional genetic diagnostics and management.