High prevalence of syndromic hearing loss in Mexican children undergoing cochlear implantation

Studies evaluating genetic sensorineural hearing loss (SNHL) in Hispanic and Latino populations using genomic technologies are lacking. Recent data has shown that Hispanic and Latino children display lower genetic diagnostic rates despite similar prevalence rates of SNHL to their Asian and White counterparts, thus negatively affecting their clinical care. Our objective was to determine the genetic contribution to SNHL in a population of Mexican children undergoing evaluation for cochlear implantation.

Pediatric patients from Mexico with severe to profound SNHL undergoing evaluation for cochlear implantation were recruited. Exome sequencing (ES) or hearing loss gene panel testing was performed. Variant pathogenicity was established in accordance to criteria established by the American College of Medical Genetics, and variants of interest were clinically confirmed via CLIA certified laboratory.

Genetic evaluation was completed for 30 Mexican children with severe to profound SNHL. A genetic cause was identified for 47% (14) of probands, and 7% (2) probands had an inconclusive result. Of the diagnoses, 10 (71%) were syndromic or likely syndromic, and 4 (29%) were nonsyndromic. Eight probands (80% of all syndromic diagnoses) were diagnosed with a syndromic form of hearing loss that mimics a nonsyndromic clinical presentation at a young age and so could not be suspected based on clinical evaluation alone without genetic testing.

This is the largest study to date to use comprehensive genomic testing for the evaluation of Mexican children with severe to profound SNHL. A significant proportion of children in this cohort were diagnosed with syndromic hearing loss. Future study in a larger cohort of Mexican children with varying degrees of hearing loss is required to improve the efficacy of genetic testing and timely medical intervention within these ethnically diverse populations.

Level 4 (cohort study).