A Locus on Distal Chromosome 10 (Ahl4) Affecting Age-Related Hearing Loss in A/J Mice

In the study, researchers identified a genetic locus on distal Chromosome 10, named ahl4, that contributes to early-onset age-related hearing loss in A/J mice. Despite sharing the same Cdh23(ahl) variant associated with hearing loss, A/J mice began to lose hearing at 4 weeks of age, significantly earlier than C57BL/6J mice. The study involved examining cochleae from A/J mice aged 0 to 20 weeks and found that hair cell loss started as early as 14 days, with the severity and extent of loss increasing rapidly over the next 2 to 5 months. This hair cell loss was more severe and widespread in A/J mice compared to B6 mice during the first 5 months. However, spiral ganglion neurons, stria vascularis cells, and vestibular hair cell densities remained normal in 20-week-old A/J mice.