The major symptoms of US are hearing impairment and an eye disorder called retinitis pigmentosa, in which vision worsens over time. Some people with US also have balance problems. Although it was first described by Albrecht Von Graefe in 1858, US was named for Charles Usher, a British eye doctor, who believed that this condition was inherited or passed from parents to their children. US is inherited or passed from parents to their children through genes. Genes are located in every cell of the body and contain the instructions that tell cells what to do.
Some genes specify traits such as hair color.
Other genes are involved in the development of body parts, such as the ear. Still others determine how parts of the body work. Sometimes genes are altered or mutated. Mutated genes may cause cells to act differently than expected. US is passed along in families by autosomal recessive inheritance, which requires two copies of the US gene before the disorder is seen.