Mild Congenital Hyperinsulinism Caused by Mutation in Human <i>Glucokinase</i> Gene

Congenital hyperinsulinism (CHI) is a rare hereditary disease characterized by the development of hypoglycemia in both infants and adult patients. CHI may be induced by activating mutations in the <i>glucokinase</i> (<i>GCK</i>) gene, which encodes the human glucokinase enzyme. This form of the disease is characterized by considerable phenotypic heterogeneity and may vary in severity of its course. We present a familial case report of mild CHI caused by a novel variant, c.212T > C (p.Val71Ala), in the <i>GCK</i> gene in a 41-year-old mother and a 15-year-old daughter. The clinical picture of hypoglycemia in the patients was not pronounced, which makes this clinical case remarkable. Moreover, a variant of uncertain clinical significance, с.1903G > A (p.Ala635Thr), in the <i>ABCC8</i> gene was detected, which may also have contributed to the course of the disease in these patients.