USH2A-related disorders are a group of inherited conditions that are associated with progressive vision loss in adolescence or early adulthood with or without hearing loss from birth.
Symptoms can present at birth and include mild hearing loss but normal vestibular (balance) responses, and loss of night vision followed by blind spots.
These conditions are caused by pathogenic (disease-causing) variants in the USH2A gene and exhibit autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Sephardic Jewish descent have a 1 in 36 chance to be a carrier. Carriers typically do not experience any symptoms.
Conditions include Usher syndrome type II and retinitis pigmentosa 39.