Hyperinsulinism hyperammonaemia (HI/HA) syndrome due to GLUD1 mutation: phenotypic variations ranging from late presentation to spontaneous resolution

Monogenic Disorders of ROS Production and the Primary Anti-Oxidative Defense

Oxidative stress, characterized by an imbalance between the production of reactive oxygen species (ROS) and the cellular anti-oxidant defense mechanisms, plays a critical role in the pathogenesis of various human diseases. Redox metabolism, comprising a network of enzymes and genes, serves as a crucial regulator of ROS levels and maintains cellular homeostasis. This review provides an overview of the most important human genes encoding for proteins involved in ROS generation, ROS detoxification, and production of reduced nicotinamide adenine dinucleotide phosphate (NADPH), and the genetic disorders that lead to dysregulation of these vital processes. Insights gained from studies on inherited monogenic metabolic diseases provide valuable basic understanding of redox metabolism and signaling, and they also help to unravel the underlying pathomechanisms that contribute to prevalent chronic disorders like cardiovascular disease, neurodegeneration, and cancer.

A Very Rare Case of Diabetes Mellitus Occurring in a Patient With Hyperinsulinism Hyperammonemia Syndrome

Background/Objective

To illustrate an unusual case of type 2 diabetes mellitus (T2DM) developing many years after the diagnosis of hyperinsulinism hyperammonemia (HI/HA) syndrome.

Case Report

This article reports about a 36-year-old female with a history of congenital hyperinsulinism due to HI/HA syndrome, which was diagnosed in infancy. The patient presented with hypoglycemia and seizures as an infant and was treated with diazoxide and a low-protein diet for many years with reduction in her hypoglycemic events. She subsequently developed T2DM >30 years later. Genetic analysis was positive for a glutamate dehydrogenase 1 gene (GLUD1) alteration. She was treated with metformin and a glucagon-like peptide 1 agonist, with significant improvement in her blood glucose control and weight loss.

Discussion

HI/HA syndrome is a rare genetic syndrome that manifests in childhood with signs and symptoms of hypoglycemia and neurologic symptoms. This is the first case reported in the literature of a patient with HI/HA syndrome due to a GLUD1 alteration who developed T2DM much later in life. Patients with this disorder usually have recurrent hypoglycemia and require long-term medical therapy or very occasionally may have a resolution. She had class 3 obesity and evidence of insulin resistance, which likely contributed to her risk of diabetes.

Conclusion

This is a rare case of T2DM presenting in a patient with HI/HA syndrome. This should be considered a possible outcome in patients with this disorder, especially in the presence of obesity.

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.

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

Congenital hyperinsulinism (CHI) is a rare disease characterized by an unregulated insulin release, leading to hypoglycaemia. It is the most frequent cause of persistent and severe hypoglycaemia in the neonatal period and early childhood. Mutations in 16 different key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, UCP2, HNF4A, HNF1A, HK1, KCNQ1, CACNA1D, FOXA2, EIF2S3, PGM1 and PMM2) that are involved in regulating the insulin secretion from pancreatic β-cells have been described to be responsible for the underlying molecular mechanisms of CHI. CHI can also be associated with specific syndromes and can be secondary to intrauterine growth restriction (IUGR), maternal diabetes, birth asphyxia, etc. It is important to diagnose and promptly initiate appropriate management as untreated hypoglycaemia can be associated with significant neurodisability. CHI can be histopathologically classified into diffuse, focal and atypical forms. Advances in molecular genetics, imaging techniques (18F-fluoro-l-dihydroxyphenylalanine positron emission tomography/computed tomography scanning), novel medical therapies and surgical advances (laparoscopic pancreatectomy) have changed the management and improved the outcome of patients with CHI. This review article provides an overview of the background, clinical presentation, diagnosis, molecular genetics and therapy for children with different forms of CHI.

Primary Dysmenorrhea: Pathophysiology, Diagnosis, and Treatment Updates

Primary dysmenorrhea (PD) is a common, disregarded, underdiagnosed, and inadequately treated complaint of both young and adult females. It is characterized by painful cramps in the lower abdomen, which start shortly before or at the onset of menses and which could last for 3 days. In particular, PD negatively impacts the quality of life (QOL) of young females and is the main reason behind their absenteeism from school or work. It is suggested that increased intrauterine secretion of prostaglandins F2α and E2 are responsible for the pelvic pain associated with this disorder. Its associated symptoms are physical and/or psychological. Its physical symptoms include headache, lethargy, sleep disturbances, tender breasts, various body pains, disturbed appetite, nausea, vomiting, constipation or diarrhea, and increased urination, whereas its psychological symptoms include mood disturbances, such as anxiety, depression, and irritability. While its diagnosis is based on patients’ history, symptoms, and physical examination, its treatment aims to improve the QOL through the administration of nonsteroidal anti-inflammatory drugs, hormonal contraceptives, and/or the use of non-pharmacological aids (e.g., topical heat application and exercise). Patients must be monitored to measure their response to treatment, assess their adherence, observe potential side effects, and perform further investigations, if needed.

Congenital Hyperinsulinism: Current Laboratory-Based Approaches to the Genetic Diagnosis of a Heterogeneous Disease

Congenital hyperinsulinism is characterised by the inappropriate release of insulin during hypoglycaemia. This potentially life-threatening disorder can occur in isolation, or present as a feature of syndromic disease. Establishing the underlying aetiology of the hyperinsulinism is critical for guiding medical management of this condition especially in children with diazoxide-unresponsive hyperinsulinism where the underlying genetics determines whether focal or diffuse pancreatic disease is present. Disease-causing single nucleotide variants affecting over 30 genes are known to cause persistent hyperinsulinism with mutations in the KATP channel genes (ABCC8 and KCNJ11) most commonly identified in children with severe persistent disease. Defects in methylation, changes in chromosome number, and large deletions and duplications disrupting multiple genes are also well described in congenital hyperinsulinism, further highlighting the genetic heterogeneity of this condition. Next-generation sequencing has revolutionised the approach to genetic testing for congenital hyperinsulinism with targeted gene panels, exome, and genome sequencing being highly sensitive methods for the analysis of multiple disease genes in a single reaction. It should though be recognised that limitations remain with next-generation sequencing with no single application able to detect all reported forms of genetic variation. This is an important consideration for hyperinsulinism genetic testing as comprehensive screening may require multiple investigations.

Preparation and field study of combined vaccine against Clostridium perfringens type A and bovine viral diarrhea virus in camels

Purpose

The key objective of this study was to formulate a local combined inactivated gel adjuvanted vaccine containing bovine viral diarrhea virus (BVDV)-1, BVDV-2 viruses and Clostridium perfringens type A toxoid. The study evaluated its ability to enhance protective active immune response in camels’ calves against these infectious pathogens under field conditions.

Materials and Methods

The local BVDV cytopathic strains and a local strain of toxigenic C. perfringens type A were used in vaccines formulation. Vaccines A and B were monovalent vaccines against C. perfringens and both strains of BVDVs, respectively. While the vaccine C was the combined vaccine used against the three agents. All vaccines were adjuvanted with Montanide gel. Sterility, safety, and potency tests were applied on the formulated vaccines. Virus neutralization and toxin anti-toxin neutralization tests were used to evaluate the immune responses.

Results

Both monovalent (vaccine A) and combined vaccines (vaccine C) showed a protective level (4.5 and 3 IU/mL, respectively) against C. perfringens from the 2nd-week post-vaccination. The titer declined to 3 and 2 IU/mL, respectively at the 5th-month post-vaccination. The titer against BVDV, the monovalent vaccine (vaccine B) reached the beak (1.95 IU/mL) at the 1st-month post-vaccination and lasted till 6th-month post-vaccination (0.92 and 0.94 IU/mL) for BVDV-1a and BVDV-2, respectively.

Conclusion

Vaccination of camels with the combined vaccine adjuvanted by Montanide gel containing C. perfringens type A toxoid and BVDV strains with 6-month intervals is recommended to protect camels safely and efficiently against such infections in the field.