This paper from March 2022 is an overview of the phenotypic presentation of Usher syndrome. Usher syndrome is classified into three distinct subtypes - USH1, USH2, and USH3. This classification is based on a combination of symptom severity, progression, and age of onset. These three subtypes are associated with nine different genes. Additional genes have been reported to be involved in another subtype called “atypical Usher syndrome,” which does not meet the current subtype definitions. Additionally, for each Usher syndrome gene, the experience of symptoms for patients can range widely. This study looked at what is known about each gene associated with Usher syndrome and the "atypical Usher syndrome" presentation. The authors suggest that given the rapid advancement of molecular genetics and discovery of additional genes associated with “atypical Usher syndrome,” the classification system should be updated.
What this means for Usher syndrome: Early and accurate diagnosis for patients with Usher syndrome is essential for ensuring effective treatment. If more accurate classifications for Usher syndrome were established, this could guide potential treatments. It would also help patients understand better how their specific condition may progress.
