Levodopa response in Parkinsonism with multiple mitochondrial DNA deletions.

We report a patient with an autosomal dominant chronic progressive external ophthalmoplegia phenotype associated with multiple mtDNA deletions in muscle from a family in which linkage analysis excluded mutations in DNA polymerase gamma (POLG), adenine nucleotide translocase (ANT-1) or C10orf2 (Twinkle). She presented with prominent Parkinsonism characterized by prolonged benefit from levodopa (L-dopa) and the later development of L-dopa induced dyskinesias and motor fluctuations. Thus L-dopa responsiveness, L-dopa induced dyskinesias and motor fluctuations may also occur in atypical Parkinsonism of mitochondrial disease, just as they may in multiple system atrophy.