Elevated plasma and/or urine levels of 3-methylglutaconic acid (MGC) can be indicative of several inborn errors of metabolism (MGC types I-V). MGC type IV is a group of disorders with varying primary etiologies, but all probably involve mitochond

rial dysfunction at some level. The ultimate primary etiology can be difficult to uncover, and testing can involve a wide array of enzymatic and molecular testing. A good diagnostic approach was published by Wortmann et al. in Brain 2009; 136-146.

Hilary Vernon, MD, PhD

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