Mutation analysis of genes associated with congenital HI in a commercial laboratory found a maternally‐transmitted novel missense variant in ABCC8 (p.Val715Met; Table 2) that was interpreted as a “variant of unknown significance.” The mother denied having symptoms of hypoglycemia; however, phenotype testing demonstrated that she was affected (shown in Table 3): a 24‐hr fasting test revealed hypoketotic hypoglycemia; an oPTT provoked an abnormal drop in plasma glucose to 65 mg/dl (3.6 mmol/l; delta 27 mg/dl or 1.5 mmol/l). Here, ABCC8 is linked to Hypoglycemia.