Prevalence and geographical distribution of Usher syndrome in Germany.

Abstract

To estimate the prevalence of Usher syndrome in Heidelberg and Mannheim and to map its geographical distribution in Germany. Usher syndrome patients were ascertained through the databases of the Low Vision Department at the University of Heidelberg, and of the patient support group Pro Retina. Ophthalmic and audiologic examinations and medical records were used to classify patients into one of the subtypes. The database of the University of Heidelberg contains 247 Usher syndrome patients, 63 with Usher syndrome type 1 (USH1) and 184 with Usher syndrome type 2 (USH2). The USH1:USH2 ratio in the Heidelberg database was 1:3. The Pro Retina database includes 248 Usher syndrome patients, 21 with USH1 and 227 with USH2. The total number of Usher syndrome patients was 424, with 75 USH1 and 349 USH2 patients; 71 patients were in both databases. The prevalence of Usher syndrome in Heidelberg and suburbs was calculated to be 6.2 per 100,000 inhabitants. There seems to be a homogeneous distribution in Germany for both subtypes. Knowledge of the high prevalence of Usher syndrome, with up to 5,000 patients in Germany, should lead to increased awareness and timely diagnosis by ophthalmologists and otologists. It should also ensure that these patients receive good support through hearing and vision aids.