Explaining Usher Syndrome
Have you ever wondered what it would be like to lose you sight or hearing? What if you were told that you would lose both slowly over the next ten years or so? That is what has been told to Rebecca and others like her.
Rebecca, 30, has a rare genetic disorder called Usher syndrome, type III. It is among the cruelest of disorders -- progressively stealing normal life away from roughly 16,000 people nationwide. And, currently, there is no treatment or cure. Rebecca lives courageously each day with the hope that a cure will be found before it's too late. My family and many others are determined to help through our involvement with the following organizations.
Why are Rebecca and others have is a condition called Usher syndrome. It is an inherited condition characterized by hearing impairment and progressive vision loss. It slowly “steals” their normal life from them. It is estimated that 50,000 people in the U.S. have Usher syndrome. Worldwide, it is the leading cause of combined deafness and blindness.
The vision loss is due to retinitis pigmentosa (RP), a degenerative condition of the retina. It usually appears during adolescence or early adulthood. Approximately 30 percent of people with RP report some degree of hearing loss, but not all of them will be diagnosed with Usher syndrome.
The hearing loss in Usher syndrome is due to a genetic mutation (alteration) affecting nerve cells in the cochlea, a sound-transmitting structure of the inner ear.
There are at least three different forms of Usher syndrome.
> Usher syndrome type 1 (USH1) patients are usually born with severe hearing loss. They experience problems with balance. These patients experience their first signs of RP, night blindness and loss of peripheral vision, usually in early adolescence.
> Usher syndrome type 2 (USH2) patients will have moderate to severe hearing impairment as newborns. Symptoms of RP typically start shortly after adolescence. These visual problems progress less rapidly than in Usher type 1. Often their hearing loss will remain stable.
> The third type of Usher syndrome (USH3) is rarer. It was documented in 1995. USH3 patients are usually born with good or only mild impairment of hearing. The loss of their hearing and vision usually starts around puberty and is progressive, getting worse over time. Balance may also be affected.
Usher syndrome is inherited in an autosomal recessive pattern. Each parent must pass on a copy of the mutated gene to the affected child in this inheritance pattern.
Genetic testing is becoming available to help people define their condition and the risk of other family members or future offspring being affected.
Currently, there is no cure for Usher Syndrome. There is research being done with vitamin A palmitate which has been shown to slow the retinal degeneration in some patients with RP and USH2. Other researchers are making excellent progress in gene therapy to treat Usher syndrome. With gene therapy, a normal gene is delivered to the retina to replace the mutated, disease-causing gene. The gene therapy may also be used to treat hearing loss.