Molecular Characterization and Management of Congenital Hyperinsulinism: A Tertiary Centre Experience

Clinical Profile and Efficacy of Long-Acting Octreotide in Hyperinsulinemic Hypoglycaemia

Introduction

Hyperinsulinemic hypoglycaemia (HH) is characterised by unregulated insulin secretion, leading to persistent non-ketotic hypoglycaemia with a lack of alternate fuel that induces a severe risk for brain damage and neurodevelopmental abnormalities. Octreotide, a somatostatin analogue, has been effectively administered as subcutaneous injections or depot preparations in diazoxide-unresponsive HH.

Methods

Children and infants with HH receiving short-acting octreotide injections were included. Anthropometric values, hypoglycaemic episodes, HbA1C, and side effects were noted from the records and were followed up for 12 months. Informed written consent was obtained from the parents before administration of a single dose of LAR (long-acting octreotide). Based on home-based glucose monitoring (HBGM), the dosage of LAR was modified, and short-acting octreotide was eventually withdrawn. The patients shared the injection's cost for cost-effectiveness. HH affects the quality of life (QoL) if not diagnosed and controlled adequately. A QoL questionnaire was given before starting LAR and after 6 months of receiving LAR, and the changes were noted accordingly.

Results

Twenty-two patients were diagnosed with HH, of which 11 infants and children were included in the study. Mutations were identified in 7 (63.63%) children. Daily octreotide could be tapered and stopped with the addition of sirolimus in one patient with an increasing dose of LAR to maintain euglycaemia. The hypoglycaemic episodes decreased with increasing dose of LAR with a decrease in the severity. Eight (72.7%) patients showed an improved lifestyle on LAR quantified through a QoL questionnaire.

Conclusion

LAR was found effective in reducing hypoglycaemic episodes with no adverse effects. The patient's parent's satisfaction was higher. Given its high cost, this trial achieved cost-effectiveness by sharing a single sitting of LAR injection.

Hyperinsulinism-hyperammonemia syndrome in two Peruvian children with refractory epilepsy

OBJECTIVES

Congenital hyperinsulinism (HI) is a heterogeneous clinical disorder with great variability in its clinical phenotype, and to date, pathogenic variants in 23 genes have been recognized.  Hyperinsulinism-hyperammonemia syndrome (HI/HA) is the second most frequent cause of this disease that shows an autosomal dominant pattern and is caused by an activating mutation of the GLUD1 gene, which responds favorably to the use of diazoxide. HI/HA syndrome presents with fasting hypoglycemia; postprandial hypoglycemia, especially in those with a high protein content (leucine); and persistent mild hyperammonemia. Neurological abnormalities, in the form of epilepsy or neurodevelopmental delay, are observed in a high percentage of patients; therefore, timely diagnosis is crucial for proper management.

CASE PRESENTATION

We report the clinical presentation of two Peruvian children that presented with epilepsy whose genetic analysis revealed a missense mutation in the GLUD1 gene, one within exon 11, at 22% mosaicism; and another within exon 7, as well as their response to diazoxide therapy. To the best of our knowledge, these are the first two cases of HI/HA syndrome reported in Peru.

CONCLUSIONS

HI/HA syndrome went unnoticed, because hypoglycemia was missed and were considered partially controlled epilepsies. A failure to recognize hypoglycemic seizures will delay diagnosis and adequate treatment, so a proper investigation could avoid irreversible neurological damage.