Recognition of Hyperinsulinaemic Hypoglycaemia in Infants with Congenital Central Hypoventilation Syndrome.

Introduction: Congenital central hypoventilation syndrome (CCHS) is a rare autosomal dominant condition due to mutations in the transcription factor PHOX2B. It is characterized by alveolar hypoventilation with symptoms of autonomic nervous system dysfunction. Hyperinsulinaemic hypoglycaemia (HH) due to glucose dysregulation caused by anomalous insulin secretion has been reported as a feature of CCHS.

Congenital hyperinsulinism and novel KDM6A duplications -resolving pathogenicity with genome and epigenetic analyses.

Context: Hyperinsulinemic hypoglycemia (HI) can be the presenting feature of Kabuki syndrome (KS), which is caused by loss-of-function variants in KMT2D or KDM6A. As these genes play a critical role in maintaining methylation status in chromatin, individuals with pathogenic variants have a disease-specific epigenomic profile -an episignature.

Objective: We evaluated the pathogenicity of three novel partial KDM6A duplications identified in three individuals presenting with neonatal-onset HI without typical features of KS at the time of genetic testing.

Low-dose diazoxide is safe and effective in infants with transient hyperinsulinism.

Objective: Transient hyperinsulinism (THI) is the most common form of recurrent hypoglycaemia in neonates beyond the first week of life. Although self-resolving, treatment can be required. Consensus guidelines recommend the lower end of the diazoxide 5-15 mg/kg/day range in THI to reduce the risk of adverse events.

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.

Phosphomannomutase 2 (PMM2) variants leading to hyperinsulinism-polycystic kidney disease are associated with early-onset inflammatory bowel disease and gastric antral foveolar hyperplasia.

Phosphomannomutase 2 (PMM2) deficiency causes Congenital Disorder of Glycosylation (PMM2-CDG), but does not have a recognised association with Inflammatory Bowel Disease (IBD). A distinct clinical syndrome of hyperinsulinism and autosomal recessive polycystic kidney disease (HIPKD) arises in the context of a specific variant in the PMM2 promotor, either in homozygosity, or compound heterozygous with a deleterious PMM2 variant. Here, we describe the development of IBD in three patients with PMM2-HIPKD, with onset of IBD at 0, 6, and 10 years of age.

The hypoglycaemia error grid: A UK-wide consensus on CGM accuracy assessment in hyperinsulinism.

Objective: Continuous Glucose Monitoring (CGM) is gaining in popularity for patients with paediatric hypoglycaemia disorders such as Congenital Hyperinsulinism (CHI), but no standard measures of accuracy or associated clinical risk are available. The small number of prior assessments of CGM accuracy in CHI have thus been incomplete. We aimed to develop a novel Hypoglycaemia Error Grid (HEG) for CGM assessment for those with CHI based on expert consensus opinion applied to a large paired (CGM/blood glucose) dataset.

Non-coding variants disrupting a tissue-specific regulatory element in HK1 cause congenital hyperinsulinism.

Gene expression is tightly regulated, with many genes exhibiting cell-specific silencing when their protein product would disrupt normal cellular function. This silencing is largely controlled by non-coding elements, and their disruption might cause human disease. We performed gene-agnostic screening of the non-coding regions to discover new molecular causes of congenital hyperinsulinism.

Spectrum of neuro-developmental disorders in children with congenital hyperinsulinism due to activating mutations in GLUD1.

Background: Hyperinsulinism/hyperammonemia (HI/HA) syndrome is the second most common type of congenital hyperinsulinism caused by an activating GLUD1 mutation.

Objective: The aim of this study was to determine the clinical profile and long-term neurological outcomes in children with HI/HA syndrome.

Method: This study is a retrospective review of patients with GLUD1 mutation, treated at two centers in the UK and Russia, over a 15-year period.

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.

Variation in Glycemic Outcomes in Focal Forms of Congenital Hyperinsulinism-The UK Perspective.

Context: In focal congenital hyperinsulinism (CHI), localized clonal expansion of pancreatic β-cells causes excess insulin secretion and severe hypoglycemia. Surgery is curative, but not all lesions are amenable to surgery.

Objective: We describe surgical and nonsurgical outcomes of focal CHI in a national cohort.

Increased referrals for congenital hyperinsulinism genetic testing in children with trisomy 21 reflects the high burden of non-genetic risk factors in this group.

Background: Hyperinsulinism results from inappropriate insulin secretion during hypoglycaemia. Down syndrome is causally linked to a number of endocrine disorders including Type 1 diabetes and neonatal diabetes. We noted a high number of individuals with Down syndrome referred for hyperinsulinism genetic testing, and therefore aimed to investigate whether the prevalence of Down syndrome was increased in our hyperinsulinism cohort compared to the population.

Clinical and genetic heterogeneity of HNF4A/HNF1A mutations in a multicentre paediatric cohort with hyperinsulinaemic hypoglycaemia.

Objective: The phenotype mediated by HNF4A/HNF1A mutations is variable and includes diazoxide-responsive hyperinsulinaemic hypoglycaemia (HH) and maturity-onset diabetes of the young (MODY).

Design: We characterised an international multicentre paediatric cohort of patients with HNF4Aor HNF1Amutations presenting with HH over a 25-year period (1995-2020).

Methods: Clinical and genetic analysis data from five centres were obtained.

Diazoxide-responsive hyperinsulinaemic hypoglycaemia in tyrosinaemia type 1.

Summary: Tyrosinaemia type 1 (TT1) is a rare inherited disorder of amino acid metabolism typically presenting with liver failure and renal tubular dysfunction. We describe three individuals with TT1 and transient hyperinsulinaemic hypoglycaemia (HH). Two siblings with TT1 and acute liver dysfunction were diagnosed with hyperinsulinaemic hypoglycaemia in the neonatal period.

Syndromic Forms of Hyperinsulinaemic Hypoglycaemia-A 15-year follow-up Study.

Objective: Hyperinsulinaemic hypoglycaemia (HH) is one of the commonest causes of hypoglycaemia in children. The molecular basis includes defects in pathways that regulate insulin release. Syndromic conditions like Beckwith-Wiedemann (BWS), Kabuki (KS) and Turner (TS) are known to be associated with a higher risk for HH.

Unusual Glycemic Presentations in a Child with a Novel Heterozygous Intragenic INSR Deletion.

Background: Mutations of the insulin receptor (INSR) gene lead to a wide spectrum of inherited insulin resistance (IR) syndromes. Among these, type A-IR, usually caused by dominant negative INSR mutations, generally presents peri-pubertally in girls.

Case: A 2.

Using referral rates for genetic testing to determine the incidence of a rare disease: The minimal incidence of congenital hyperinsulinism in the UK is 1 in 28,389.

Congenital hyperinsulinism (CHI) is a significant cause of hypoglycaemia in neonates and infants with the potential for permanent neurologic injury. Accurate calculations of the incidence of rare diseases such as CHI are important as they inform health care planning and can aid interpretation of genetic testing results when assessing the frequency of variants in large-scale, unselected sequencing databases. Whilst minimal incidence rates have been calculated for four European countries, the incidence of CHI in the UK is not known.

Diazoxide-induced pulmonary hypertension in hyperinsulinaemic hypoglycaemia: Recommendations from a multicentre study in the United Kingdom.

Objective: Diazoxide is first-line treatment for hyperinsulinaemic hypoglycaemia (HH) but diazoxide-induced pulmonary hypertension (PH) can occur. We aim to characterize the incidence and risk factors of diazoxide-induced PH in a large HH cohort to provide recommendations for anticipating and preventing PH in diazoxide-treated patients with HH.

Design And Patients: Retrospective cohort study involving four UK regional HH centres; review of case notes of HH patients on diazoxide.

Persistent hyperinsulinaemic hypoglycaemia in children with Rubinstein-Taybi syndrome.

Objective: Genetic aetiology remains unknown in up to 50% of patients with persistent hyperinsulinaemic hypoglycaemia (HH). Several syndromes are associated with HH. We report Rubinstein-Taybi syndrome (RSTS) as one of the possible causes of persistent HH.

Sirolimus: Efficacy and Complications in Children With Hyperinsulinemic Hypoglycemia: A 5-Year Follow-Up Study.

Introduction: Sirolimus, a mammalian target of rapamycin inhibitor, has been used in congenital hyperinsulinism (CHI) unresponsive to diazoxide and octreotide. Reported response to sirolimus is variable, with high incidence of adverse effects. To the best of our knowledge, we report the largest group of CHI patients treated with sirolimus followed for the longest period to date.

Partial diazoxide responsiveness in a neonate with hyperinsulinism due to homozygous ABCC8 mutation.

We report a case of partial diazoxide responsiveness in a child with severe congenital hyperinsulinaemic hypoglycaemia (CHI) due to a homozygous ABCC8 mutation. A term baby, with birth weight 3.8 kg, born to consanguineous parents presented on day 1 of life with hypoglycaemia.

The Use of a Long-Acting Somatostatin Analogue (Lanreotide) in Three Children with Focal Forms of Congenital Hyperinsulinaemic Hypoglycaemia.

Background: A long-acting somatostatin analogue (lanreotide) is used in the management of a diazoxide-unresponsive diffuse form of congenital hyperinsulinism (CHI). However, no reports of its use in patients with the focal form of CHI exist. Case 1: A 1-month-old boy diagnosed with diazoxide-unresponsive CHI due to a paternal heterozygous ABCC8 gene mutation showed partial response to octreotide.

Post-Prandial Hyperinsulinaemic Hypoglycaemia after Oesophageal Surgery in Children.

Introduction: Post-prandial hyperinsulinaemic hypoglycaemia (PPHH) is a recognized complication of various gastric surgeries in children, but rarely reported after oesophageal atresia repair. We report 2 children diagnosed with PPHH after oesophageal surgery and the challenges of their management. Case 1: A 2-year-old boy diagnosed with oesophageal atresia at birth was surgically repaired requiring 6 oesophageal dilatations in the first year of life.

Sirolimus precipitating diabetes mellitus in a patient with congenital hyperinsulinaemic hypoglycaemia due to autosomal dominant ABCC8 mutation.

Background: Sirolimus (mTOR inhibitor) is proven to be effective in children with congenital hyperinsulinism (CHI). Studies in animals suggest that sirolimus may have diabetogenic actions. However, its role in precipitating diabetes mellitus (DM) in children with CHI has not been reported.