Mudd et al. (Mol Genet Metab. 2011 Nov 12.) reported 2 patients with mtDNA depletion syndrome and elevations in S-adenosylmethionine and methionine. After careful investigation, they conclude that these analytes are not elevated due to additional primary defects in associated pathways (i.e. glycine N-methyltransferase). They  hypothesize that the primary mitochondrial defect disrupts the normal usage of AdoMet by mitochondria.

This is an interesting finding, and brings to attention the potential vast array of metabolic abnormalities that can be seen in primary mitochondrial defects in multiple seemingly unassociated pathways.

Hilary Vernon, MD PhD

http://dx.doi.org/10.1036/ommbid.127