A potential novel mutation site for type 7 maturity-onset diabetes of the young

Objective To search for the potential novel mutation site and to discuss related clinical characteristics by collecting detailed information and testing the gene of a family with highly suspected type 7 maturity-onset diabetes of the young (MODY7). Methods The gene test was conducted in a 28-year-old female patient with a 20-year course of non-ketosis-prone diabetes, with non-effective long-term insulin treatment, and a 3-generation family history of diabetes, and the patient was found to carry KLF11 gene mutation. Thus, the clinical data of family members were collected and investigated, and the pathogenic gene was tested. Firstly, the proband was searched for pathogenic genes by chip-capture high-throughput sequencing method. Then the mutation sites were verified by Sanger sequencing technology, and other family members were searched for the same mutation sites by the Sanger sequencing technology. Results A total of two members of the family was found to have heterozygous mutation of KLF11 gene: c. 920C>T (No. 920 nucleotide of the coding region mutated from cytosine to thymine), resulting in the change of corresponding amino acid p. P307L (No. 307 amino acid changed from proline to leucine), which was a missense mutation and was consistent with their clinical diagnosis of diabetes. Conclusions The family in this study had a family history of diabetes caused by the missense mutation of KLF11 gene. This is the first report of the mutation site of c. 920C >T (p.P307l), which may be a new mutation site of MODY7. Key words: Maturity-onset diabetes of the young, type 7; Transcription factor KLF11; Missense mutation