USH2A retinitis pigmentosa is a genetic disorder that causes vision loss due to mutations in the USH2A gene. The USH2A gene encodes usherin, a protein in the retina and inner ear. Mutations in the USH2A gene cause the breakdown of photoreceptors, the light-sensing cells in the retina. This leads to progressive vision loss. Early symptoms include night blindness and loss of side vision, also known as tunnel vision. Symptoms usually develop between the ages of 10 and 30, but can start in childhood. USH2A retinitis pigmentosa can be non-syndromic or syndromic, known as Usher syndrome type 2. Non-syndromic RP is not associated with other signs and symptoms. A medical professional can diagnose retinitis pigmentosa with lab tests. Retinal function can be assessed with an electroretinogram (ERG), and optical coherence tomography (OCT) can assess structural alterations. At this time, there's no cure for retinitis pigmentosa, but medications can help treat complications.