对2018年8月南京医科大学附属儿童医院诊治的1例B淋巴细胞激酶(n BLK)基因突变致青少年发病的成人糖尿病11型( MODY11)患儿的临床资料进行回顾性分析，对其家系进行糖尿病调查。先证者，男，13岁，因“发现高血糖0.5年”入院，病初当地医院诊断为1型糖尿病。查体：身高169.2 cm，体质量65.5 kg，体质量指数22.9 kg/mn 2，体型偏胖，无黑棘皮。实验室检查：空腹血糖11.79 mmol/L，空腹胰岛素18.05 mmol/L，空腹C肽1.12 mmol/L，糖化血红蛋白12.0%，糖尿病相关自身抗体均阴性。该家系连续4代共11例糖尿病患者，其中8例使用胰岛素治疗，3例口服降糖药物治疗。先证者及其父母采用全外显子基因测序，发现先证者及其母亲n BLK基因第9外显子杂合突变(c.809C>T)，导致氨基酸改变p.T270M (苏氨酸>蛋氨酸)。MODY临床容易被误诊为1型或2型糖尿病。MODY11的病例较罕见，临床多表现为超重或肥胖，血清胰岛素分泌相对不足，常需要胰岛素治疗。n “,”The clinical data of a patient with maturity-onset diabetes of the young 11 (MODY11) caused by B lymphocyte kinase(n BLK) gene mutations in Children′s Hospital Affiliated to Nanjing Medical University in August 2018 were retrospectively analyzed.The diabetes mellitus epidemiologic investigation was carried out on the patient′s family.The 13-year-old boy was diagnosed with type 1 diabetes at the local hospital 6 months ago.Physical examination showed that he was 65.5 kg in weight, 169.2 cm in height and 22.9 kg/mn 2 in the body mass index.He was overweight without acanthosis nigricans.Laboratory measurements revealed fasting blood glucose 11.79 mmol/L, fasting insulin 18.05 mmol/L, and fasting C-peptide 1.12 mmol/L.The glycosylated hemoglobin was 12.0%, while the islet antibodies were all negative.Among 4 consecutive generations of this family, 11 members presented with diabetes, 8 cases of who were treated with insulin and 3 cases with oral hypoglycemic drugs.The whole exome sequencing identified a heterozygous mutation in exon 9 of n BLK (c.809C>T) in this patient and his mother.This mutation caused the amino acid change p. T270M (threonine>methionine). Many cases of MODY are misdiagnosed as either type 1 diabetes or type 2 diabetes.MODY11 is rare, mostly characterized by overweight or obesity, insufficient serum insulin secretion and commonly insulin dependence.n