Is genetic testing for Usher syndrome available?
At this time, genetic testing for Usher syndrome is done only as part of research projects. This is due to many factors. Usher syndrome is not caused by only one gene. So far, 10 Usher genes have been mapped: 7 for type I, 3 for type II, and 1 for type 3. There are still more genes to find. A few of these genes have been sequenced and described. These are MYO7A, harmonin, CDH23, PCDH15, all causing type I; and usherin, causing type II. Although finding the genes is an important advance in the fight against Usher syndrome, it is merely the first step in a long series. Additional study is required to pinpoint more of the genes causing Usher syndrome, characterize these genes, and determine how the mutated genes cause Usher syndrome. Several researchers throughout the world are working on Usher syndrome. Findings from this research may one day allow treatments for Usher syndrome to be developed.
