A family with hyperinsulinemia caused by a novel mutation of SLC16A1 gene / 中华内分泌代谢杂志

Objective:Congenital hyperinsulinemia is a heterogeneous disorder characterized by severe hypoglycemia due to dysregulated insulin secretion. Sixteen genes have been reported to be associated with congenital hyperinsulinemia. In this study, whole exome sequencing was performed on a patient with obesity, hyperinsulinemia, and postprandial hypoglycemia to further explore its genetic etiology.Methods:The clinical data and peripheral blood of a patient with hyperinsulinemia and his family members were collected. Genomic DNA was extracted from the peripheral blood. Sanger sequencing and pedigree verification were performed on the pathogenic variants filtered by whole-exome sequencing. The function of the mutation sites was analyzed by bioinformatics software.Results:The proband presented with obesity, hyperinsulinemia, and postprandial hypoglycemia, but without exercise-induced hypoglycemia. A heterozygous SCL16A1 gene c. 1259A>G(p.K420R) mutation was identified in the proband. Co-segregated analysis showed that the c. 1259A>G mutation was also found in his father and brother, who had obesity and hyperinsulinemia, which was consistent with autosomal dominant inheritance. The mutation c. 1259A>G was predicted to be pathogenic by the MutationTaster, FATHMM-MKL, PolyPhen2, and CADD programs, and has not been reported in HGDM database yet, which was considered to be a novel mutation.Conclusion:This study reported a patient with hyperinsulinemia caused by a new mutation of SCL16A1 gene, which expanded our understanding of the pathogenic mutation spectrum of hyperinsulinemia.

Clinical characteristics and gene mutations analysis of 56 patients with congenital hyperinsulinism / 中华实用儿科临床杂志

Objective To analyze the clinical characteristics and gene mutations of 56 patients with congenital hyperinsulinism(CHI)and to provide a theoretical basis for clinical diagnosis and treatment of CHI.Methods Fifty-six children who were diagnosed as CHI between February 2002 and January 2016 in Beijing Children's Hospital Affiliated to Capital Medical University were selected as research subjects.A retrospective study was done about the clinical data and the treatment procedures of the 56 patients,such as perinatal conditions,clinical manifestations,laboratory data,treatments,prognosis and so on.Polymerase chain reaction(PCR)-DNA technology or next-generation sequencing technology was used to analyze the CHI relevant genes of the 56 patients.Results Thirty of the 56 patients carried CHI gene mutation.(1)Twenty-three of 56 patients(41.0％)carried ABCC8/KCNJ11 gene mutations:4 of 23 patients carried complex heterozygous mutation,1 of 23 patients carried both ABCC8 and KCNJ11 gene mutation,1 of 23 patients carried maternally inherited ABCC8 gene mutation,12 of 23 patients carried paternally inherited ABCC8 gene mutation,1 of 23 patients carried paternally inherited KCNJ11 gene mutation,3 of 23 patients carried de novo ABCC8 gene mutation,1 of 23 patients had unknown genetic way,19 of 23 patients were treated with Diazoxide,2 of 19 patients were responsive to Diazoxide,7 of 19 patients were unresponsive to Diazoxide and 10 of 19 patients were uncertain to Diazoxide.(2)Five of 56 patients(8.9％)carried GLUD1 gene mutation,4 of 5 patients were treated with Diazoxide and they were all responsive to Diazoxide.(3)One of 56 patients(1.7％)carried de novo GCK gene mutation,responsive to Diazoxide treatment.(4)One of 56 patients(1.7％)carried maternally inherited SLC16A1 gene mutation,responsive to Diazo-xide treatment.Conclusions The ABCC8 gene and GLUD1 gene mutation are the main causative genes of CHI.The GCK gene and SLC16A1 gene mutation are in the minority.Most ABCC8 gene and KCNJ11 gene mutation are unresponsive to Diazoxide treatment.