Congenital hyperinsulinism: recent updates on molecular mechanisms, diagnosis and management

Successful Management of an Infant with Congenital Focal Hyperinsulinism with No Apparent Lesion During Surgery

Congenital hyperinsulinism (HI) is the leading cause of persistent hypoglycemia in infants and children. Focal pancreatic lesions account for 30-40% of cases with congenital HI. With early diagnosis, these patients can be treated by resection of the lesion, making long-term medical care unnecessary. In this case, a 5-day-old newborn boy presented with convulsion due to severe and persistent hypoglycemia at his hospitalization in neonatal intensive care unit. Laboratory studies revealed very low levels of ketone bodies with inappropriately normal insulin levels during hypoglycemia. The patient was unresponsive to diazoxide treatment. The molecular genetic analysis revealed a heterozygous pathogenic variant in the ABCC8 gene. 18F-DOPA-PET/CT scan showed increased uptake of 18F-DOPA consistent with focal lesion at the tail of the pancreas. A focal pancreatectomy operation was performed when he was three months old. Histopathological evaluation confirmed focal endocrine cell hyperplasia. Hypoglycemia did not recur after the operation. CHI patients with ABCC8 / KCNJ11 mutation are not easy to manage with pharmacotheraphy. In the case of an identifiable focal lesion associated with CHI, surgery is the most preferred option. In focal CHI, as in our case, the lesion may not be visually evident and requires a surgeon experienced in CHI.

The obesity-related mutation gene on nonalcoholic fatty liver disease

The prevalence of overweight and obesity is increasing, leading to metabolic-associated fatty liver disease (MAFLD) characterized by excessive accumulation of liver fat and a risk of developing hepatocellular carcinoma (HCC). The driver gene mutations may play the roles of passengers that occur in single 'hotspots' and can promote tumorigenesis from benign to malignant lesions. We investigated the impact of high body weight and BMI on HCC survival using The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) dataset. To explore the effects of obesity-related gene mutations on HCC, we collected driver mutation genes in 34 TCGA patients with BMI ≥ 27 and 23 TCGA patients with BMI < 27. The digital PCR performing the PBMC samples for the variant rate by clinical cohort of 96 NAFLD patients. Our analysis showed that obesity leads to significantly worse survival outcomes in HCC. Using cbioportal, we identified 414 driver mutation genes in patients with obesity and 127 driver mutation genes in non-obese patients. Functional analysis showed that obese-related genes significantly enriched the regulated lipid and insulin pathways in HCC. The insulin secretion pathway in patients with obesity HCC-specific survival identified ABCC8 and PRKCB as significant genes (p < 0.001). It revealed significant differences in gene mutation and gene expression profiles compared to non-obese patients. The digital PCR test ABCC8 variants were detected in PBMC samples and caused a 14.5% variant rate, significantly higher than that of non-obese NAFLD patients. The study findings showed that the gene ABCC8 was a patient with the obesity-related gene in NAFLD, which provides the probability that ABCC8 mutation contributes to the pre-cancer lesion biomarker for HCC.

Mild Congenital Hyperinsulinism Caused by Mutation in Human Glucokinase Gene

Congenital hyperinsulinism (CHI) is a rare hereditary disease characterized by the development of hypoglycemia in both infants and adult patients. CHI may be induced by activating mutations in the glucokinase (GCK) gene, which encodes the human glucokinase enzyme. This form of the disease is characterized by considerable phenotypic heterogeneity and may vary in severity of its course. We present a familial case report of mild CHI caused by a novel variant, c.212T > C (p.Val71Ala), in the GCK gene in a 41-year-old mother and a 15-year-old daughter. The clinical picture of hypoglycemia in the patients was not pronounced, which makes this clinical case remarkable. Moreover, a variant of uncertain clinical significance, с.1903G > A (p.Ala635Thr), in the ABCC8 gene was detected, which may also have contributed to the course of the disease in these patients.

Non-surgical Treatment May be Appropriate for Most Chinese Children With Monogenic Congenital Hyperinsulinism Based on a Retrospective Study of 121 Patients

Objective: There is a notable absence of extensive Chinese studies involving monogenic congenital hyperinsulinism (CHI). The purpose of this large retrospective Chinese cohort with monogenic CHI from a national children's medical center was to analyze the genetic and clinical characteristics. Methods: We compared clinical characteristics grouped by genotypes based on CHI-targeted next-generation sequencing (tNGS) and performed subgroup analyses by onset time. Results: Totally, 121 non-consanguineous patients were enrolled. Among them, 79 patients (65.3%) had variants in ATP-sensitive potassium channel (KATP) genes (62 heterozygotes and 17 compound heterozygotes), 35 (28.9%) in glutamate dehydrogenase 1 (GLUD1), and 7 (5.8%) in rare genes (hydroxyacyl-CoA dehydrogenase [HADH], glucokinase [GCK], and hepatocyte nuclear factor 4 alpha [HNF4A]). Ten patients had ATP binding cassette subfamily C member 8 (ABCC8) variants (p.G111R), and 12 had GLUD1 variants (p.S498L), suggesting two potential founder variants. Three ABCC8 variants (p.G1478R, p.L580_S581insFASL, and p.S986⁣ ∗ ) and two HNF4A variants (p.R63W and p.V382I) were previously reported to be associated with diabetes. Non-surgical treatment was effective in 65.9% of patients with KATP variants, while in 100% of those with non-KATP variants. For the subgroup of KATP variants, neonatal-onset patients tended to present with mild symptoms (67.9% versus 19.3%), had a higher proportion of surgical intervention (24.5% versus 3.8%), and displayed higher levels of serum insulin and C-peptide than non-neonatal onset ones (p < 0.001). Conclusion: The absence of homozygous variants in KATP genes and a quite higher proportion of GLUD1 variants than previous cohorts, may explain a high response rate of non-surgical treatment in this study. Surgery might be considered for neonatal-onset children, especially when KATP variants were discovered but not for those carried variants reported to cause diabetes in later life. While expanding the genotypic spectrum, we also highlight the clinical significance of genetic screening.

Standardised practices in the networked management of congenital hyperinsulinism: a UK national collaborative consensus

Congenital hyperinsulinism (CHI) is a condition characterised by severe and recurrent hypoglycaemia in infants and young children caused by inappropriate insulin over-secretion. CHI is of heterogeneous aetiology with a significant genetic component and is often unresponsive to standard medical therapy options. The treatment of CHI can be multifaceted and complex, requiring multidisciplinary input. It is important to manage hypoglycaemia in CHI promptly as the risk of long-term neurodisability arising from neuroglycopaenia is high. The UK CHI consensus on the practice and management of CHI was developed to optimise and harmonise clinical management of patients in centres specialising in CHI as well as in non-specialist centres engaged in collaborative, networked models of care. Using current best practice and a consensus approach, it provides guidance and practical advice in the domains of diagnosis, clinical assessment and treatment to mitigate hypoglycaemia risk and improve long term outcomes for health and well-being.

KATP channel mutations in congenital hyperinsulinism: Progress and challenges towards mechanism-based therapies

Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycemia in infancy/childhood and is a serious condition associated with severe recurrent attacks of hypoglycemia due to dysregulated insulin secretion. Timely diagnosis and effective treatment are crucial to prevent severe hypoglycemia that may lead to life-long neurological complications. In pancreatic β-cells, adenosine triphosphate (ATP)-sensitive K+ (KATP) channels are a central regulator of insulin secretion vital for glucose homeostasis. Genetic defects that lead to loss of expression or function of KATP channels are the most common cause of HI (KATP-HI). Much progress has been made in our understanding of the molecular genetics and pathophysiology of KATP-HI in the past decades; however, treatment remains challenging, in particular for patients with diffuse disease who do not respond to the KATP channel activator diazoxide. In this review, we discuss current approaches and limitations on the diagnosis and treatment of KATP-HI, and offer perspectives on alternative therapeutic strategies.

[Electroencephalogram features in children with congenital hyperinsulinism treated according to the international protocol in Russian Federation]

BACKGROUND

Congenital hyperinsulinism (CHI) is a rare life-threatening disease characterised by persistent hypoglycaemia as a result of inappropriate insulin secretion, which can lead to irreversible neurological defects in infants.

AIM

To evaluate neurophysiological characteristics of central nervous system in children with congenital hyperinsulinism treated according to the international protocol in Russian Federation.

MATERIALS AND METHODS

Our retrospective, prospective cohort study included 73 patients who received treatment for CHI according to the current international protocol at different departments of the Almazov National Medical Research Centre from 2017 to 2022. All patients underwent a comprehensive examination, including electroencephalography (EEG).

RESULTS

Among 73 patients with CHI, 35% (23) had focal form of the disease, 65% had non-focal form (49% (39) - diffuse form, 16% (11) - atypical form). All patients with focal form of CHI had a recovery as an outcome.Analysing the EEG data we found that paroxysmal activity was recorded in 23 patients (32%), 50 patients did not have paroxysmal activity (68%). Diffuse changes were observed in 47 patients (64%), whereas 26 patients (36%) were absent of it. By constructing Kaplan-Meier curves we found that the alpha rhythm is formed significantly (p=0.026) earlier in patients with a focal form of CHI.

CONCLUSION

CHI patients treated according to the international guidelines in Russian Federation show rather positive neurological outcome. We established that alpha rhythm earliest formation is associated with focal form of CHI.

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.

Insight into hypoglycemia frequency in congenital hyperinsulinism: evaluation of a large UK CGM dataset

INTRODUCTION

Hypoglycemia is often recurrent and severe in patients with congenital hyperinsulinism (CHI). However, there is little information regarding frequency or patterns of episodes to inform clinical management and future trial design.

RESEARCH DESIGN AND METHODS

We aimed to describe frequency and patterns of hypoglycemia by varying thresholds through a large continuous glucose monitoring (CGM) dataset. Through the UK CHI centers of excellence, data were analyzed from patients with CHI over a 5-year period. Hypoglycemia thresholds of 3.0 (H3.0), 3.5 (H3.5) and 3.9 (H3.9) mmol/L were used to test threshold change on hypoglycemia frequencies.

RESULTS

From 63 patients, 3.4 million data points, representing 32 years of monitoring, were analyzed. By UK consensus threshold H3.5, patients experienced a mean 1.3 hypoglycemic episodes per day. Per cent time hypoglycemic increased from 1.2% to 3.3% to 6.9% when threshold changed from H3.0 to H3.5 and H3.9. Merged data showed periodicity of hypoglycemia risk in 24-hour periods in all patients.

CONCLUSIONS

We have evaluated a large dataset to provide a comprehensive picture of the frequency and patterns of hypoglycemia for patients with CHI in the UK. These data establish a baseline risk of hypoglycemia by CGM and provide a framework for clinical management and clinical trial design.

Role of Actionable Genes in Pursuing a True Approach of Precision Medicine in Monogenic Diabetes

Monogenic diabetes is a genetic disorder caused by one or more variations in a single gene. It encompasses a broad spectrum of heterogeneous conditions, including neonatal diabetes, maturity onset diabetes of the young (MODY) and syndromic diabetes, affecting 1-5% of patients with diabetes. Some of these variants are harbored by genes whose altered function can be tackled by specific actions ("actionable genes"). In suspected patients, molecular diagnosis allows the implementation of effective approaches of precision medicine so as to allow individual interventions aimed to prevent, mitigate or delay clinical outcomes. This review will almost exclusively concentrate on the clinical strategy that can be specifically pursued in carriers of mutations in "actionable genes", including ABCC8, KCNJ11, GCK, HNF1A, HNF4A, HNF1B, PPARG, GATA4 and GATA6. For each of them we will provide a short background on what is known about gene function and dysfunction. Then, we will discuss how the identification of their mutations in individuals with this form of diabetes, can be used in daily clinical practice to implement specific monitoring and treatments. We hope this article will help clinical diabetologists carefully consider who of their patients deserves timely genetic testing for monogenic diabetes.

Health-Related Quality of Life of Children and Adolescents With Congenital Hyperinsulinism - A Scoping Review

Introduction

Despite improvements in diagnosis and therapeutic advances in treatment, congenital hyperinsulinism (CHI) remains a severe disease with high patient impairment. We aimed to review the literature on Health-related Quality of Life in children and adolescents with congenital hyperinsulinism and summarize the findings.

Materials and Methods

For this scoping review, a literature search was conducted in PubMed and Web of Science in May 2021. Inclusion and exclusion criteria for the selection of articles were defined a priori.

Results

Two hundred and forty-five (245) articles were identified through the search and screened on the basis of title and abstract. The full texts of forty articles were then assessed. Finally, four articles (published 2012-2020) describing Health-related Quality of Life in children and adolescents with congenital hyperinsulinism were included. The study designs were heterogeneous and included cross-sectional observational studies (n=2), clinical trials (n =1), and case reports (n=1) with different sample sizes. Three studies were conducted in European countries and one in Japan. The results for Health-related Quality of Life revealed inconsistencies.

Conclusion

There are only a few studies looking at Health-related Quality of Life in children and adolescents with congenital hyperinsulinism. To gain a comprehensive understanding of the impact of congenital hyperinsulinism on Health-related Quality of Life in children and adolescents, it is necessary to use both generic and condition-specific instruments to measure Health-related Quality of Life of young patients in larger samples, to collect longitudinal data, and to consider qualitative research approaches.