Down-sloping sensorineural hearing loss is an easy-to-overlook issue for its significance. However, it can hamper efficient communication and in-depth social interaction, and learning ability is severely damaged especially in people in their teens and twenties. Even people with the disease usually don’t seek for medical advice or supportive devices because converstion might be possible in a quiet condition. In this study, authors revealed the genotypic and phenotypic spectrum of the down-sloping hearing loss. In detail, one-third of the case has genetic causes and among them, LOXHD1-related hearing loss (DFNB77) is the dominant form. Further information about a potential founder allele and a genotype-phenotype correlation was well introduced, which will promote the application of precision medicine in the field. (By Bong Jik Kim, https://jmg.bmj.com/content/early/2021/03/21/jmedgenet-2020-107594)