ESPE Abstracts

Backgrounds: Congenital hyperinsulinism (CHI) is a rare condition linked to several genetic, metabolic, and growth disorders in which there is dysregulated insulin secretion. Biochemical evidence of insulin-induced hypoglycemia is a prerequisite for genetic testing; however, there are no established criteria for the age at diagnosis of CHI. This study aims to investigate the genetic and clinical features of patients with CHI in a single center.

Methods: A total of ten patients with CHI were enrolled from July 2013 to March 2022. Diagnoses were based on biochemical and genetic testing.

Results: At the time of diagnosis, the initial insulin level was more than 2.0 μU/mL in all 10 patients with hypoglycemia (glucose <50 mg/dl). Among 10 patients with CHI, 6 were born as SGA or LGA. Hypoglycemia occurred within the first 7 days of birth in 7 out of 10 patients, and 2 occurred after 6 months. Among seven patients with hypoglycemia within seven days of birth, hypoglycemia was alleviated within two months in five patients (71%). Two out of three patients with hypoglycemia after seven days of age required continuous treatment. Nine out of a total of 10 patients were treated with diazoxide, and two of them were non-responsive to diazoxide. One patient improved only with short-term hydrocortisone. Developmental delay was observed in 2 out of 10 patients. Of the nine patients subjected to genetic testing, six (66.6%) were found to have genetic defects (ABCC8, KCNJ11, GCK, GCKR, NEUROD1), and five (83.3%) of these six mutations were novel variants. Of note, two genes, GCKR and NEUROD1 , are presumed to be susceptibility genes related to CHI. Compared with six patients with genetic positive and four with genetic negative, the average duration of hypoglycemia and treatment were higher in the group with genetic defects, respectively.

Conclusions: This study delineated 10 CHI patients regarding genotypes and clinical courses in Korea. The timely identification of genotypes could help predict the phenotypes and decide on appropriate treatment options.