ABSTRACT
Objective To report a 33-year-old man with post-headache stroke-like episodes,with whom ischemic changes were found in basal ganglia and occipital-temporal lobe and muscle biopsy revealed abnormal mitochondrial structure and function without regular mutations detected in mtDNA.Methods Gene chip technique was used to detect the mutation of whole sequence of mtDNA,and direct sequencing technique was used to confirm the mutations.Results Three mutations were found.A new mutation in the mitochondrial cytochrome C oxidase subunit 1 (MTCO1),a T→C transition at nucleotide position 6253 resulted in conservative methionine transferring to threonine.His mother also held the mutation,which was not found in 98 control samples.So T6253C was considered the nosogenetic mutation.Conclusion This is the first time to report a mutation in MTCO1 responsible of MELAS.