SPG7 mutations are a common cause of undiagnosed ataxia

Late-onset ataxias are clinically and etiologically diverse. Patients rarely have defining clinical features, and many remain classified as idiopathic, despite extensive clinical, metabolic, and genetic investigations. Here we show that mutations in a gene known to cause hereditary spastic paraplegia ( SPG7 ) are a major cause of unexplained ataxia presenting in mid-adult life.