MECP2 and metabolic disease: Due to these data, in context with a growing appreciation that mitochondrial dysfunction may play a role in RTT, and because anaplerotic diet therapy has aided a wide range of metabolic diseases, we hypothesized that there may be a deficit in general fuel substrate utilization in Mecp2 KO, irrespective of specific derangements, that could benefit from anaplerotic therapy using triheptanoin.