USH 2A

Role in the organism:

The USH2A gene is primarily expressed in the retina and cochlea and encodes a protein that has several properties that indicate that it is an extracellular matrix protein (a protein that has a function in connecting cells of some tissue). Although its exact function is unknown, it is probably required for proper development of the eye and inner ear.

Role in the disorder (state):

Mutations in the USH2A gene result in a form of Usher syndrome characterized by hearing and vision problems. Patients with the most severe form of the disease (type I) are probably deaf from birth, have an imbalance and visual disturbance caused by retinitis pigmentosa (degenerative eye condition) by 10 years of age. Other types of USH2A mutations cause type II Usher syndrome, followed by moderate to severe birth defects and retinitis pigmentosa up to 20 years of age. There is also type III Usher syndrome, with mild symptoms and deafness and blindness occur later in life.