We describe two siblings with childhood onset, slowly progressive generalized dystonia and cerebellar signs. Brain neuroimaging revealed white matter abnormalities compatible with a neuronal degenerative disorder. An extensive evaluation for mitochondrial, metabolic, autoimmune or other known neurodegenerative disorders did not reveal the etiology of the disease. During a three-year follow-up other neurological signs appeared, but progression was very slow. We believe that our patients have a new type of a leukoencephalopathy with slowly progressive dystonia and cerebellar signs.