[G14453A mutation in mitochondrial myopathy encephalomyopathy with lactic acidosis and stroke-like episodes].

OBJECTIVE: To analyz mitochondrial DNA mutation in one case of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). METHODS: The patient, a 10-years-old boy,clinically diagnosed as MELAS. The clinical information was collected, and the normal mitochondrial mutations (such as A3243G, A8344G, T8993G/C, G13513A etc) were excluded. PCR-sequencing was used to analyz the whole-mitochondrial genome (16.6 kb), and PCR-RFLP was used to confirm the mutations. RESULTS: m.G14453A mutation was detected from the patient's peripheral blood and urine, but it was not found in his parents and 100 normal controls. The m.G14453A mutation was confirmed by PCR-RFLP, and mutation ratio of in blood was 56.8% and urine was 72.5%. The activity of complex I was decreased (67.6 nmol·min⁻¹·mg⁻¹). This was the first report that m.G14453A mutation could lead to MELAS in China according www.mitomap.org web and NCBI. CONCLUSION: m.G14453A mutation is one of the causative mutations in MELAS, but the mechanism of the mutation should be studied in future.