AUH deficiency came to be known as 3MGA type I, with other disorders associated with 3MGA classified as 3MGA type II (Barth syndrome), 3MGA type III (defects in OPA3) and 3MGA type IV historically referring to miscellaneous mitochondrial disorders not genetically defined.55, 56. Here, AUH is linked to hyperinsulinemic hypoglycemia, familial, 4.