# Congenital Hyperinsulinism in Neonates: Diagnostic Challenges and Management in Two Cases With KCNJ11 and ABCC8 Mutation

**Authors:** Adele Figuccia, Giuliana Vitaliti, Claudia Avanti, Luca Di Bella, Salvino Marcello Vitaliti

PMC · DOI: 10.7759/cureus.103829 · 2026-02-18

## TL;DR

This paper discusses two neonates with congenital hyperinsulinism, a rare condition causing low blood sugar, and highlights the importance of genetic testing and proper treatment.

## Contribution

The study presents two rare cases of neonatal congenital hyperinsulinism and emphasizes the role of genetic testing in diagnosis and treatment.

## Key findings

- Persistent neonatal hypoglycemia was linked to mutations in KCNJ11 and ABCC8 genes.
- Standard glucose infusions and diazoxide were ineffective, but octreotide stabilized blood sugar levels.
- Genetic testing confirmed pathogenic variants and guided targeted treatment.

## Abstract

We report two cases of persistent neonatal hypoglycemia associated with mutations in the KCNJ11 and ABCC8 genes, encoding the Kir6.2 and SUR1 subunits of the adenosine triphosphate-sensitive potassium channel. In both cases, symptoms were non-specific and initially attributed to other conditions, including suspected infection. Standard treatment with enteral and parenteral glucose infusions failed to restore euglycemia. Diazoxide was administered without a clinical response. Both patients were then treated with octreotide, resulting in stabilization of glycemic levels. Genetic testing confirmed the presence of pathogenic variants consistent with congenital hyperinsulinism. Early identification and targeted management were crucial to achieving metabolic control.

## Linked entities

- **Genes:** KCNJ11 (potassium inwardly rectifying channel subfamily J member 11) [NCBI Gene 3767], ABCC8 (ATP binding cassette subfamily C member 8) [NCBI Gene 6833]
- **Proteins:** KCNJ11 (potassium inwardly rectifying channel subfamily J member 11), ABCC8 (ATP binding cassette subfamily C member 8)
- **Chemicals:** glucose (PubChem CID 5793), diazoxide (PubChem CID 3019), octreotide (PubChem CID 448601)
- **Diseases:** congenital hyperinsulinism (MONDO:0017182), hypoglycemia (MONDO:0004946)

## Full-text entities

- **Genes:** ABCC8 (ATP binding cassette subfamily C member 8) [NCBI Gene 6833] {aka ABC36, HHF1, HI, HRINS, MODY12, MRP8}, KCNJ11 (potassium inwardly rectifying channel subfamily J member 11) [NCBI Gene 3767] {aka BIR, HHF2, IKATP, KIR6.2, MODY13, PHHI}
- **Diseases:** infection (MESH:D007239), Congenital Hyperinsulinism (MESH:D044903), neonatal hypoglycemia (MESH:D007003)
- **Chemicals:** octreotide (MESH:D015282), glucose (MESH:D005947), Diazoxide (MESH:D003981)
- **Species:** Homo sapiens (human, species) [taxon 9606]

---
Source: https://tomesphere.com/paper/PMC13003185