Scientists from Columbia University have uncovered a number of rare genetic variants implicated in age-related hearing loss (ARHL), expanding knowledge around the mechanisms that underlie this common sensory deficit. ARHL affects around 50 percent of all adults 75 years of age and older, and while many studies have linked common variants to increased susceptibility to ARHL, the role of rare variants is poorly understood. To investigate, the researchers analyzed exome and imputed data from white European UK Biobank volunteers, performing both single-variant and rare-variant aggregate association analyses using self-reported ARHL phenotypes. As reported in the European Journal of Human Genetics this week, they uncovered signification associations between ARHL and rare variants in several genes, including ones known to underline Mendelian nonsyndromic hearing loss. One newly identified gene is known to be involved in apoptosis that is widely expressed in the inner ear, strengthening the role of programmed cell death in ARHL. "Although most findings were replicated in independent samples of white Europeans, additional studies are necessary to elucidate whether these variants/genes play a role in the genetic etiology of ARHL in other populations," the study's authors note.