Sixteen family members carried the ABCC8 or KCNJ11 mutations; only two had hypoglycemia detected at birth and four others reported symptoms of hypoglycemia.
Furthermore, it is demonstrated that the KCNJ11E23K polymorphism in association to either of the two genes' DNA methylation may have protective role against sulfonylurea-induced hypoglycemia.
Congenital hyperinsulinemic hypoglycemia (HI) is a heterogeneous genetic disorder of insulin secretion characterized by persistent hypoglycemia, most commonly associated with inactivating mutations of the β-cell ATP-sensitive K(+) channel (K(ATP) channel) genes ABCC8 (encoding SUR1) and KCNJ11(encoding Kir6.2).
Dominant inactivating ABCC8 and KCNJ11 mutations are less frequent, but are usually associated with a milder form of hypoglycaemia that is responsive to diazoxide therapy.
Therefore, the effects of the Glu23Lys polymorphism in the KCNJ11 (KIR6.2) gene (potassium inwardly rectifying channel, subfamily J, member 11) on impaired hypoglycaemia awareness in 217 patients with T1D were studied.