Mitochondrial recessive ataxia syndrome

Mitochondrial recessive ataxia syndrome (MIRAS) is the mitochondrial disease, that is caused by mutations of the POLG1 gene encoding the mitochondrial DNA polymerase gamma enzyme. MIRAS includes the sensory ataxia neuropathy dysarthria and ophthalmoplegia (SANDO) and Spinocerebellar ataxia with epilepsy (SCAE). MIRAS is a common cause of autosomal recessive juvenile- or adult-onset ataxia, at least in Scandinavia. Most cases of SANDO present with an initial stage of sensory neuropathy, a second stage of progressive external ophahlmoplegia and dysarthria, which is then followed by other symptoms, often with epilepsia or myoclonus.