Heterozygous lys169Glu mutation of glucokinase gene in a Chinese family having glucokinase-maturity-onset diabetes of the young (GCK-MODY)

We report a 24-year-old female with early-onset and persistent mild fasting hyperglycemia due to glucokinase-maturity-onset diabetes of the young (GCK-MODY). A c.505A>G (p. Lys169Glu) missense mutation of the GCK gene was identified. In silico analysis indicated that the mutation affected a conserved amino acid and is disease-causing. This report describes GCK-MODY in a Chinese family and stresses that in managing this condition it is important to avoid unnecessary drug treatment and excessive anxiety about mild hyperglycemia.