While some people have specific and textbook-like symptoms of a distinct syndrome such as Leber hereditary optic neuropathy (LHON), many individuals with mitochondrial disease have a variety of symptoms involving multiple body systems or organs. Common symptoms can include generalized development disability, features of autism spectrum disorder, intellectual disabilities, muscle weakness, seizures, peripheral neuropathy, cardiomyopathy, liver and kidney disease, vision loss (ophthalmoplegia, retinitis pigmentosa), hearing loss, and diabetes mellitus.