Three cases with m.8993T>G mutation, two patients with the novel m.5523T>G and m.5559A>G mutations in the tRNA(Trp) gene, and two individuals with the undescribed m.9478T>C mutation in the cytochrome c oxidase subunit III (COXIII) gene were found with LS.
We report a nine-year-old boy with the features of Leigh syndrome (LS) and a severe cytochrome-c oxidase (COX) deficiency with a single thymidine insertion at nucleotide position 5537 (T 5537i) in the tRNA Trp gene of mitochondrial DNA.
SURF1-mutations were identified in three out of four cases with Leigh syndrome while a mutation in the mitochondrial tRNA (trp) gene was identified in the fourth.