Glucokinase-maturity onset diabetes mellitus in the young suggested by factory-calibrated glucose monitoring data: a case report

[摘要] Glucokinase has an important role in regulating glycolysis as a glucose sensor in liver and pancreatic β cells. Glucokinase-maturity onset diabetes in young (GCK-MODY also known as MODY2) is caused by autosomal dominant gene mutation of the GCK gene; it is characterized by mild fasting hyperglycemia and small 2-h glucose increment during 75 g-oral glucose tolerance test (OGTT) as well as near-normal postprandial glucose variabilities. A 10-year-old girl with family history of diabetes visited her physician after being found positive for urinary glucose by school medical checkup. She received a diagnosis of diabetes based on the laboratory data: 75 g-OGTT (mild fasting hyperglycemia and small 2-h glucose increment) and factory-calibrated glucose monitoring (mild elevation of average glucose level and near-normal glycemic variability), which raised suspicion of GCK-MODY. She was then referred to our institution for genetic examination, which revealed a GCKT: p.E442X) in the proband as well as in her mother and maternal grandmother, who had been receiving anti-diabetes medications without knowing that they had GCK-MODY specifically. GCK-MODY cases show incidence of microvascular and macrovascular diseases similar to that of normal subjects, and their glucose levels are adequately controlled without anti-diabetes drug use. Thus, early and definitive diagnosis of MODY2 by genetic testing is important to avoid unnecessary medication.

[学科分类] 内分泌与代谢学

[关键词] Glucokinase (GCK);Factory-calibrated glucose monitoring (FGM);Glucokinase-maturity onset diabetes mellitus in young (GCK-MODY);Maturity onset diabetes mellitus in young 2 (MODY2)