It is argued that this rare disease, since the princeps description in 1964 only reported in England (1986) and the U.S.A (1986), is most likely a singular type of mitochondrial encephalopathy: it is associated with Leber's optic atrophy, and the NMR changes observed have been signalled in other mitochondrial encephalomyelopathies, such as Leigh's disease and MELAS.
These results indicate that erythrocyte transketolase activity is not altered in subacute necrotising encephalomyelopathy and is unlikely to be of value for the diagnosis of Leigh's disease.
The mutation in the mitochondrial ATP synthase subunit 6 gene (ATP6T8993G) was identified in a male infant who died at age 15 months of Leigh syndrome.
A mitochondrial DNA mutation at nucleotide pair 14459 of the NADH dehydrogenase subunit 6 gene associated with maternally inherited Leber hereditary optic neuropathy and dystonia.
Cytoplasmic transfer of the mtDNA nt 8993 T-->G (ATP6) point mutation associated with Leigh syndrome into mtDNA-less cells demonstrates cosegregation with a decrease in state III respiration and ADP/O ratio.
A 5-year-old child with clinical and radiologic evidence of Leigh syndrome (LS) showed a T-->C mutation at position nt 8993 in the mitochondrial DNA (instead of the more common T-->G substitution), resulting in an amino acid change from a highly conserved leucine to proline in subunit 6 of mitochondrial ATPase.