Clinical and genetic analysis of five pedigree with maturity-onset diabetes of the young type 2 / 中华内分泌代谢杂志

ABSTRACT

Objective:To explore the clinical and molecular genetic characteristics of patients with maturity-onset diabetes of the young type 2(MODY2).Methods:Clinical data and laboratory results were collected from five MODY2 patients and their family members diagnosed in the Department of Endocrinology, Genetics, and Metabolism of Xi ′an Children′s Hospital in the recent two years. Whole exome sequencing was carried out on every proband to identify potential variants, then the suspected variants were verified with Sanger sequencing in family numbers.Results:Among the 5 probands, except for proband 4 who presented with polydipsia and polyuria, hyperglycemia in the rest of the children was accidentally identified. Urine routine, urinary protein, and blood lipid of the five probands were all normal, and HbA 1C was between 5.96% and 8.15%. Moreover, an important discovery in this study was that proband 5 had insulin resistance(IRS), which was different from previous studies. It was confirmed by genetic analysis that a glucokinase(GCK) gene variant existed in every MODY2 pedigree. There were four GCK variants in this study, including c. 146C>T(p.T49I), c. 1237T>G(p.Y413D), c. 683C>T(p.T228M) and c. 952G>T(p.G318W), among which the C. 1237T>G(P.y413d) and C. 952G>T(P.G318W) had not been reported till now. All probands received lifestyle intervention, and the blood glucose control was relatively stable. Conclusion:There is MODY2 patient complicated with IRS. MODY2 patients can be controlled well by lifestyle interventions. In addition, we discovered two novel variants of GCK, which extend the mutation spectrum of this gene.