摘要目的:报道并总结5个葡萄糖激酶(GCK)基因突变导致的青少年成人起病型糖尿病2型(MODY2)家系临床表现和分子遗传学特征。方法:收集先证者临床资料和生化检查。采集先证者及一级家属外周血，采用二代测序法进行全外显子组基因检测。与数据库对比筛选可疑致病位点进行Sanger测序验证。结果:5位先证者均表现出轻度空腹高血糖，HbA 1C<7.5%，无口渴、多饮、多尿症状。5个家系中存在6个突变位点，其中M1：c.555delT(p.Leu186Cysfs Ter19)和M3：c.263T>A(p.Met88Lys)未见文献报道。随访过程中，5位先证者除2位妊娠女性建议根据胎儿基因型，必要时应用胰岛素治疗外，余均行生活方式干预。 结论:在符合MODY诊断标准的患者中，对于轻度高血糖、家族史明确的儿童或妊娠期女性应进行MODY2筛查，GCK基因检测是诊断金标准，精准诊断将有利于选择更合适的治疗方案。

abstractsObjective:To summarize the clinical manifestations and molecular genetic characteristics of 5 families with maturity-onset diabetes mellitus of the young 2 (MODY2) caused by glucokinase (GCK) gene mutations.Methods:Clinical data and biochemical results of probands were collected. Peripheral blood samples of probands and first-degree family members were collected and whole exome gene was detected using second-generation sequencing. After comparing against the database, the suspected pathogenic sites were selected for Sanger sequencing verification.Results:All the 5 probands presented with mild fasting hyperglycemia, HbA 1C<7.5%, and no symptoms of thirst, polydipsia or polyuria. There were 6 mutants in 5 families, including M1: c.555delT (P.leu186CysFS Ter19) and M3: c. 263T>A (p.Met88Lys) which haven′t been reported before. During the follow-up, all probands received life-style intervention, except 2 pregnant women who should consider insulin treatment if necessary according to fetal genotypes. Conclusion:Among patients who meet the diagnostic criteria for MODY, MODY2 screening should be performed for children or pregnant women with mild hyperglycemia and family history. GCK gene detection is the gold standard for diagnosis, and accurate diagnosis will be conducive to the selection of appropriate treatment.