We developed an
oligonucleotide biochip for synchronous multiplex detection of 31 known
mitochondrial DNA mutations associated with
MELAS (
Mitochondrial encephalomyopathy with
lactic acidosis and
stroke-like episodes) and
MERRF (
Myoclonic epilepsy with ragged red fibers). Allele-specific
oligonucleotide probes were covalently immobilized on
aldehyde modified glass slides, and then hybridized with Cy5-labled
DNA fragments amplified from sample DNAs by a multiplex asymmetric PCR (MAP) method. Five patients with
MELAS, 5 patients with
MERRF and 20 healthy controls were investigated using the
oligonucleotide biochip. The results showed that all the cases with
MELAS had an A3243G mutation in the MT-TL1 gene. In the
MERRF group, 4 cases were found to be an A8344G mutation and 1 case was a T8356C mutation, and both mutations were in the MT-TK gene. In the healthy controls, none of the 31 related mutations was found. The results of the
DNA biochip were consistent with those by
DNA sequencing. Clearly, the
DNA biochip combined with MAP method would become a valuable tool in multiplex detecting of the point mutations in
mtDNA leading to
MELAS and/or
MERRF syndrome. Moreover, this biochip format could be modified to extend to the screening scope of SNPs for any other human
mitochondrial diseases.