Maturity-onset diabetes of the young 11 caused by B lymphocyte kinase mutation in a family / 中华实用儿科临床杂志

ABSTRACT

The clinical data of a patient with maturity-onset diabetes of the young 11 (MODY11) caused by B lymphocyte kinase( 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/m 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 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.