The Medical Genetics team, which is the only referral center in the Maritime Provinces for inborn errors of metabolism, has not diagnosed nor been made aware of any cases of CPT II deficiency that were missed by the newborn screen since 2005, although there could be mild myopathic CPT II deficiency patients who have yet to present clinically. The gene discussed is CPT2; the disease is hyperinsulinemic hypoglycemia, familial, 4.