Читать книгу A Practical Approach to Special Care in Dentistry - Группа авторов - Страница 154

 The prevalence of hearing impairment in children and adults is substantially higher in low‐ to medium‐income countries than in high‐income countries; the regions with the highest prevalence of hearing impairment are southern Asia, sub‐Saharan Africa, Central/Eastern Europe and Central Asia

 A significant percentage of cases of non‐syndromic deafness have a genetic origin; a number of mutations (especially in the GJB2 gene) are common in Middle Eastern countries, where carriers belonging to numerous ethnic groups have been identified