[A three-year follow-up observation of a pedigree of maturity onset diabetes of the young caused by a novel mutation of glucokinase and literature review].

Objective: To explore the clinical characteristics and follow-up outcomes of a pedigree of maturity onset diabetes of the young (MODY) induced by a novel mutation of glucokinase (GCK). Methods: The clinical features and laboratory data of a pedigree diagnosed with GCK-MODY in Peking Union Medical College Hospital was analyzed. Genomic DNA was extracted, and Sanger sequencing was performed to detect the gene mutation of the family members. The proband and her father were followed up for 3 years. Wanfang and PubMed were used to search literatures on follow-up studies for treatment of GCK-MOYD. Results: Both the proband and her father were found to have a novel mutation on the GCK gene located in exo10 c.1348G.T (p. Ala450Thr). The proband was treated with diet and exercise control only. At the end of the follow-up, her fasting plasma glucose (FPG, 6.8 mmol/L), 2 h postprandial plasma glucose (2hPG, 7.4 mmol/L), and glycated hemoglobin (HbA1c, 6.3%) were all within the control targets. Additionally, the levels homeostasis model assessment of insulin resistance (HOMA-IR) tended to improved comparing to that at baseline (4.09 to 2.32), and glucose disposition index (DI) was improved compared with baseline (16.22 to 20.05). As to the proband's father, the treatment with insulin plus acarbose was converted to sulfonylureas monotherapy. His FPG and 2hPG mostly were within the target range, and the levels of HbA1c were significantly reduced by 0.5%-0.7% when compared to that at baseline. The HOMA-IR or islet beta cell function was comparable to those at baseline. Conclusions: Screening patients whose clinical performance meets GCK-MODY and their family members with proper genetic testing is of great importance to reduce misdiagnosis of GCK-MODY, so as to obtain a better glucose control without unnecessary over-treatment and protect islet beta cell function.