2.4. MITOCHONDRIAL IN COMMON DISEASES
The demonstration that np 14459 mutation in ND6 can cause generalised dystonia has lent support to the concept that mitochondrial defects may be a factor in the cause of movement disorders such as dystonia and Parkinson's disease. A survey of dystonia patient blood platelets for OXPHOS deficiency has revealed that a substantial proportion harbor complex I defects (53). MPTP (1- methyl-4-phenyl-I,2,3,6-tetrahydropyridine), a contaminant of illicit drugs, is a complex 1 inhibitor and can cause Parkinson's disease (54-56), and Parkinson's patients have been reported to have complex I defects in their brain substantia nigra (57, 58) and in their blood platelets (59). Hence, at least some movement disorder patients are likely to be the product of mitochondrial defects and some may harbor mtDNA mutations.