MODY10 caused by c.309-314del CCAGCT insGCGC mutation of the insulin gene: a case report.

Objective: This study aims to report the clinical features and gene mutation of a rare MODY10 patient in China.

Methods: This study summarizes the clinical data of a MODY10 child in the Endocrine Department of our hospital and an analysis and discussion of the results of the gene sequencing of the child.

Results: The child was a two-year-old boy. The main reason for his visit to our hospital was "founding hyperglycemia for 3 days". The fasting blood glucose was between 8.1-10.7 mmol/L, and two-hour postprandial blood glucose was between 10.6-12.6 mmol/L. Glycosylated hemoglobin was 8.5%, fasting C-peptide was 0.6 ng/mL, fasting insulin was 2.9 μIU/mL, and the islet antibody series were all negative. Whole-genome/exon sequencing results: Exon 3 of the insulin gene in the child carried a c.309-314del CCAGCT insGCGC heterozygous mutation. The mutation was a nonsense mutation, and family sequencing showed that the mutation originated from the mother of the child. The mother of the child was diagnosed with diabetes when she was a year old and developed bilateral fundus hemorrhage and right retinal detachment at the age of 23.

Conclusion: Among Chinese children, the insulin gene c.309-314del CCAGCT insGCGC mutation may induce MODY10. For diabetic children with a negative islet autoantibody, gene detection and analysis is helpful for the diagnosis and typing of MODY.