Forty‐one percent of patients had very long‐chain acyl‐CoA dehydrogenase (VLCAD) deficiency, 54% LCHAD or MTP deficiency, and 5% carnitine palmitoyltransferase 2 (CPT2) deficiency. The gene discussed is CPT2; the disease is hyperinsulinemic hypoglycemia, familial, 4.