Usher Syndrome: Genetics and Molecular Links of Hearing Loss and Directions for Therapy

Frontiers in Genetics

Rodney J. Dilley¹  Zi Ying Ng²  Meg Whatley²  Marcus D. Atlas³  Abbie Francis⁴  Xin Ee Khoh⁵  Elaine Y. M. Wong⁶ 

[1] Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth, WA, Australia;Ear Science Institute Australia, Nedlands, WA, Australia;Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia;Emergency Medicine, The University of Western Australia, Nedlands, WA, Australia;School of Human Sciences, The University of Western Australia, Nedlands, WA, Australia;School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia;

关键词: hearing loss;    Usher syndrome;    hair cell;    stereocilia;    retinitis pigmentosa;    photoreceptor;   

DOI  :  10.3389/fgene.2020.565216

来源: DOAJ

【 摘 要 】

Usher syndrome (USH) is an autosomal recessive (AR) disorder that permanently and severely affects the senses of hearing, vision, and balance. Three clinically distinct types of USH have been identified, decreasing in severity from Type 1 to 3, with symptoms of sensorineural hearing loss (SNHL), retinitis pigmentosa (RP), and vestibular dysfunction. There are currently nine confirmed and two suspected USH-causative genes, and a further three candidate loci have been mapped. The proteins encoded by these genes form complexes that play critical roles in the development and maintenance of cellular structures within the inner ear and retina, which have minimal capacity for repair or regeneration. In the cochlea, stereocilia are located on the apical surface of inner ear hair cells (HC) and are responsible for transducing mechanical stimuli from sound pressure waves into chemical signals. These signals are then detected by the auditory nerve fibers, transmitted to the brain and interpreted as sound. Disease-causing mutations in USH genes can destabilize the tip links that bind the stereocilia to each other, and cause defects in protein trafficking and stereocilia bundle morphology, thereby inhibiting mechanosensory transduction. This review summarizes the current knowledge on Usher syndrome with a particular emphasis on mutations in USH genes, USH protein structures, and functional analyses in animal models. Currently, there is no cure for USH. However, the genetic therapies that are rapidly developing will benefit from this compilation of detailed genetic information to identify the most effective strategies for restoring functional USH proteins.

【 授权许可】

Unknown