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

To analyz mitochondrial DNA mutation in one case of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS).

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.

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.

m.G14453A mutation is one of the causative mutations in MELAS, but the mechanism of the mutation should be studied in future.