OBJECTIVES: To detect the presence of the otoferlin A1090E variant and investigate its potential correlation with severe to profound non-syndromic hereditary sensorineural hearing loss (NSHSHL) in Pakistani cochlear implant recipients.  

METHODS: This case-control study, conducted from January to December 2022, comprised 100 cases of age 6 months to 10 years of severe to profound NSHSHL who had undergone cochlear implant at ENT Department CMH Rawalpindi, and 100 healthy age matched individuals recruited from CMH Rawalpindi. Blood samples underwent DNA extraction, polymerase chain reaction, and subsequent restriction fragment length polymorphism (RFLP) analysis at the Center for Research in Experimental and Applied Medicine, Army Medical College, Rawalpindi.

RESULTS: Mean age of wild homozygous genotype CC, mutant homozygous genotype AA and heterozygous genotype CA was 1.38±0.49; 1.50±0.53 and 1.71±0.49years respectively. Under the recessive model, the A1090E variant did not correlate with NSHSHL, evidenced by the odds ratio for mutant homozygous genotype AA at 0.23. The variant's genotype deviated from Hardy-Weinberg Equilibrium (p<0.0001). Among 100 NSHSHL cases, 79, 13, and 8 exhibited wild genotype CC, mutant genotype AA, and heterozygous genotype CA, respectively. In the analysis of gender, A1090E variant in OTOF, females had no risk of deafness with heterozygous (OR=1.00) or mutant genotype (OR=0.27). Similarly, males exhibited no risk with CA and AA genotypes (OR=0.69 and 0.12).

CONCLUSION: Despite the detection of the otoferlin A1090E variant in both cases and controls, suggesting a protective role in hearing loss, it did not exhibit an association with disease risk in the study population.