Usher syndrome, type 3 the rarest form of Usher syndrome, (See: Usher syndrome) is a condition that affects both hearing and vision.
In Usher syndrome, type 3 the individual is usually born with normal hearing and vision, but both progressively worsen through childhood and adolescence. Many individuals with Usher syndrome type 3 have normal or near-normal balance, but this may worsen overtime as the ability to hear well decreases. Although type 3 has a later onset than the other types, it may still slowly progress to full deafness or blindness over time. The vision loss in Usher syndrome, type 3 is also caused by Retinitis pigmentosa (RP) (See: Retinitis pigmentosa). Usher syndrome, type 3 is rarer than the other types (1 and 2), which may make diagnosis more difficult. However, the diagnostic process is similar and requires detailed vision evaluations, hearing tests, and balance testing. Genetic testing is available and necessary to identify the underlying genetic cause and specific type of Usher syndrome. There is currently no cure for Usher syndrome type 3; however, there are treatment options that may enable the individual to hear or see better depending on the severity of symptoms.
Usher syndrome type 3 is inherited or passed through families in an autosomal recessive manner. This means that two copies of the changed (mutated) gene are needed to produce the symptoms of Usher syndrome. In recessive conditions, both parents are unaffected carriers. Each child born to two affected carriers has a 25% chance of being affected. If your child has been diagnosed with Type 3, Usher syndrome, contact your doctor or genetic counselor to discus the most current treatment options.