Shumpei Yasuda

By Shumpei P. Yasuda, Yuki Miyasaka and Yoshiaki Kikkawa

Acquired hearing loss, which includes age-related hearing loss and noise-induced hearing loss, is a common hearing impairment and shows phenotypic variability. One reason for phenotypic variability is influence of genetic background. The modifiers underlying genetic background are modulated and advance the hearing phenotypes through gene-gene interactions with other etiological genetic factors. Moreover, the modifiers play a role in the susceptibility of environmental hearing risk factors, namely, the strength and weakness of environmental susceptibility often modulate and advance hearing phenotypes via gene-environment interactions. The complicated gene-gene and gene-environment interactions make genetic analysis of acquired hearing loss difficult. In particular, the effects of environmental factors cannot be completely excluded or controlled. Although genome-wide approaches to identify genetic modifiers have proven challenging in humans, the responsible genes and mutations are widely unknown. In this chapter, we suggest that mouse models are useful for studying genetic background effects for acquired hearing loss. The genetic analysis of mouse models identified the genetic modifiers. We review the genetic research in mouse models for acquired hearing loss to identify and confirm the modifiers by both forward and reverse genetics approaches.

Part of the book: An Excursus into Hearing Loss