Age-related hearing loss in four Italian genetic isolates: an epidemiological study

The objective of this study was to estimate the prevalence Of hearing impairment ill four genetically isolated Italian villages (Carlantino, Campora, Gioi-Cardile, and Stoccareddo), 1682 subjects were recruited from all the individuals participating in a multidisciplinary study. They underwent otoscopy and pure-tone audiometry and completed it questionnaire. The audiological data show that the percentage of impaired people increases with age and ill particular becomes relevant aged over 40. For this reason we decided to compare the PTA values of individuals aged 40 or older. The PTA values, of Stoccareddo and Carlantino are statistically different front PTAs of the other villages. Campora and Gioi-Cardile. both located within the Cilento National Park, have similar middle-low frequency PTA values while sonic differences are present at high frequencies. Using pedigrees it was possible to calculate the heritability of the trait. For Carlantino and Gioi-Cardile the percentage of the phenotype variation attributable to genetic variation is not significant. while for Campora file heritability value is 0.49 (p = 0.01) suggesting, that genetic factors may have an important role.