Given that those with loss of function variants in KCNQ1 may be prone to post-prandial hypoglycemia due to increased insulin release from the pancreas (13), increased vigilance is warranted when prescribing beta-blockers to those with both KCNQ1 variants and the CPT1A p.P479L variant. The gene discussed is KCNQ1; the disease is Hypoglycemia.