OBJECTIVETo analyze clinical characteristics, genetic mutation and therapeutic effect of seven patients diagnosed with congenital hyperinsulinism(CHI).

METHODSClinical data for the patients was retrospectively analyzed.

RESULTSAll patients presented with hyperinsulinism(serum insulin:2.0-58.4 mU/L),even after hypoglycemia (blood glucose: 0.7-2.39 mmol/L) has developed. Mutations were identified in 4 patients (57.1%), which included a heterozygous c.262C to T(p.R88C) mutation in exon 4 of the UCP2 gene, a heterozygous c.1495C to A(p.G499C) mutation in exon 12 of the GLUD1 gene, a heterozygous c.1493C to T(p.S498L) mutation in exon 1 of the GLUD1 gene, and a heterozygous c.4432G to A(p.G1478R) mutation in exon 37 of the ABCC8 gene. The patient carrying a maternally inherited ABCC8 mutation was treated with cornstarch and had his blood glucose kept normal. All other patients responded well to diazoxide.

CONCLUSIONA genetic diagnosis was attained for 51.7% of patients in this study. Mild CHI patients can have their blood glucose controlled by giving cornstarch. Diazoxide is safe and effective for most CHI patients.