Genetyczne podłoże zespołu Ushera w kontekście patologii molekularnej narzÄ du słuchu i wzroku

Usher syndrome (USH) is the most common form of simultaneous loss of hearing and vision. USH is autosomal recessive disorder, clinically and genetically heterogenous. It is characterised by congenital sensorineural hearing loss, retinitis pigmentosa and in some cases by vestibular defect. Based on the symptoms observed in patients, USH is classified into three types (1, 2 and 3). To date, eleven genes with causative mutations have been identified. Proteins encoded by these genes are part of a functional complex which is present in humans hair cells in the inner ear and in photoreceptor cells in the retina. This complex is the most important in the development of the stereocilia and it is essential in a proper functioning of calyceal processes in photoreceptor cells. Disruption of proteins involved in this complex leads to Usher syndrome. In this review, we focus on molecular pathophysiology of USH with an emphasis on USH etiology, genotype-phenotype correlation, characterization of USH genes, protein complexes and their functions in human tissues.