of MDS [4]. Nevertheless, our own experience indicates that these four
genes can be screened in infantile patients who exhibit cholestatic
hepatopathy, lactic acidosis (increased lactate/pyruvate ratio), developmental
delay and motor hypotonia, as well as showing histological evidence
of MDS such as an increase in dysmorphic mitochondria.
Although we did not test for C10orf2, we identified MPV17 mutations
in all four patients.
In the liver of a patient with hepatocerebral MDS, the mitochondrial
DNA copy number is profoundly reduced and mitochondrial respiratory
chain activities are decreased, except complex II that is encoded by the
nuclear DNA. However, these measurements were not available for our
patients. Instead, we directly screened for genomic mutations in the
genes responsible for this condition. We cannot conclude that MPV17
is the most common gene responsible for hepatocerebral MDS in Korean
or other East Asian populations but we suggest that MPV17 can be the
first gene to be screened in MDS patients in these populations