Nonetheless, in rare instances bioenergetic therapies do provide major disease modifying, and even life-saving, benefit, including some of the same therapies that failed in other disease settings, for instance, CoQ10 therapy in individuals with defects in CoQ10 biosynthesis64, and a ketogenic diet to provide an alternative fuel source for patients with impaired glucose uptake into the brain (GLUT1 deficiency)65. Here, SLC2A1 is linked to hyperinsulinemic hypoglycemia, familial, 4.