<unk>  (DRPLA) is an autosomal dominant spinocerebellar degeneration caused by an expansion of a CAG repeat encoding a polyglutamine tract in the atrophin-1 protein. It is also known as Haw River Syndrome and Naito–Oyanagi disease. Although this condition was perhaps first described by Smith et al. in 1958, and several sporadic cases have been reported from Western countries, this disorder seems to be very rare except in Japan. There are at least eight neurodegenerative diseases that are caused by expanded CAG repeats encoding polyglutamine (polyQ) stretches (see: Trinucleotide repeat disorder). The expanded CAG repeats create an adverse gain-of-function mutation in the gene products. Of these diseases, DRPLA is most similar to Huntington's disease.
Dentatorubral–pallidoluysian atrophy
Cerebellar abiotrophy
Central chromatolysis
Corticobasal degeneration
Olivopontocerebellar atrophy
Spinal muscular atrophy with lower extremity predominance 1
Cerebellar degeneration
Multi/minicore myopathy