A 2ND MISSENSE MUTATION IN THE MITOCHONDRIAL ATPASE-6 GENE IN LEIGHS SYNDROME

By direct sequencing, we have discovered a novel heteroplasmic mutation (T-->C) at nucleotide position 8993 in the mitochondrial ATPase 6 gene in a family with Leigh's syndrome. Another mutation in the same codon (T8993G) has been reported before in Leigh's syndrome. As these two mutations led to different amino acid substitutions, it provides strong evidence for the relevance of ATP synthase dysfunction in maternally inherited Leigh's syndrome.