ESPE Abstracts

Introduction: Hyperinsulinemic hypoglycemia is one of the most common causes of severe and persistent hypoglycemia in neonates and children. Early diagnosis and appropriate treatment prevent brain damage due to recurrent hypoglycemia. Genetic examination often can guide the treatment. The most common affected genes are the ABCC8 and KCNJ11 genes, which encode the SUR1 and Kir6.2 K_ATP channels, respectively. Here, a neonate with a novel variant in ABCC8 gene and her genotype-phenotype relationship is presented.

Case: Her genetic analysis was reported as an diazoxide unresponsive missense mutation, due to previous neighbor mutations. Discontinuation of diazoxide treatment was made based on genetic result but she had hypoglycemia again. Hypoglycemia improved when diazoxide was added to therapy. She was followed up as normoglycemic with diazoxide and octreotide until the age of three. When she was three years-old, octreotide treatment was switched to a long-acting release form (LAR) due to family request. Diazoxide was discontinued six months after this treatment. Also, LAR dose requirement decreased over time. Now, she is five year-old and neurodevelopment is appropriate for the age, and the follow-up continues without drug-related side effects. Anthropometric and laboratory findings in the last control are given in Table-1.

Discussion-Conclusion: As a result, the genetic examination is important in guiding treatment in patients with HH. However, the genotype-phenotype relationship may not always be clear. After the partial response to diazoxide, LAR treatment was started and diazoxide was not needed anymore in our case. This situation is thought to be due to the decrease in the severity of the disease with age, or an unknown mechanism of action of LAR treatment on the K_ATP channel. It is very important to discuss the cases with HH in terms of guiding clinical follow-up and treatment.