Facts about Usher Syndrome
USHER SYNDROME IS THE MOST COMMON GENETIC CAUSE OF COMBINED DEAFNESS AND BLINDNESS.
More than 400,000 people are affected by this disorder worldwide.
Usher syndrome impacts three major senses in the body:
Vision: Vision loss in Usher syndrome is caused by a progressive vision disorder known as retinitis pigmentosa (RP). RP causes the light-sensing cells in the retina to gradually deteriorate, initially resulting in night blindness, followed by a narrowing of the visual field, commonly known as tunnel vision.
Hearing: Children with Usher syndrome are born with or develop hearing loss. It’s estimated that upward of 10 percent of people with congenital bilateral, sensorineural hearing loss have Usher syndrome.
Balance: Balance is achieved and maintained through input from your eyes, the vestibular organs in the inner ear and the sensory systems of the body, such as the skin, muscles and joints. Thus, people with Usher syndrome suffer from severe balance issues due to vestibular dysfunction.
There are three clinical types: Type 1, Type 2 and Type 3, which are distinguished by the severity and age when the signs and symptoms appear. There are at least eleven different genetic types of Usher syndrome, as determined by the genes that are involved. There are six different genes that cause Usher Type 1, three that cause Usher Type 2, and two that cause Usher Type 3. One cannot determine the genetic type by clinical testing; DNA testing is the only reliable way of determining the true genetic type.
For more information visit: The Usher Syndrome Coalition