Seven patients with a definitive diagnosis of NMDs or MDs were identified: two patients with ACAD9 deficiency (Patient 1 and Patient 2); two patients with MYH7-related myopathy (Patient 3 and Patient 4); one patient with desminopathy (Patient 5); two patients with mitochondrial myopathy (one with MT-TL1 mutation (Patient 6) and one with MTO1 mutation (Patient 7)). The gene discussed is MCAT; the disease is hyperinsulinemic hypoglycemia, familial, 4.