Numerous mutations in the POLG1 have been described recently, with various clinical presentations [5,6] including autosomal dominant and autosomal recessive familial external ophthalmoplegia (PEO) [7-10], autosomal recessive sensory ataxic neuropathy with dysarthria and ophthalmoplegia (SANDO) [11], a mixed sensory and cerebellar ataxic syndrome with epilepsy [12,13], parkinsonism [14,15] and Alpers' hepatocerebral syndrome [16-19]. Here, POLG is linked to Parkinson disease.