Insulinoma in childhood: a retrospective review of 22 patients from one referral centre.

Background: Insulinomas are very rare in childhood with sparse knowledge on the clinical aspects and the presence of Multiple Endocrine Neoplasia type 1 (MEN1). Methods: We conducted a retrospective review of patients diagnosed with insulinoma between 1995 and 2021, presenting to one referral centre in Russia. Clinical, biochemical, genetic, imaging and histological data were collected. In addition, follow-up and family data were obtained. Results: A total of twenty-two children aged 5 to 16 years were identified. The median (range) gap between the first hypoglycaemia symptoms and diagnosis was 10 (1-46) months. Twelve children (55%) were misdiagnosed to have epilepsy and were treated with anticonvulsants before hypoglycemia was revealed. Contrast enhanced MRI and/or CT were accurate to localize the lesion in 82% (n=18). Five patients (23%) had multiple pancreatic lesions. All children underwent surgical treatment. The median (range) diameter of removed tumors was 1.5 (0.3-6) cm. Histopathological studies confirmed the presence of insulinoma in all cases. Immunohistochemical studies revealed G2 differentiation grade in 10 out of 17 cases. Two patients were diagnosed with metastatic insulinoma. One of them had metastases at the time of insulinoma diagnosis, while the other was diagnosed with liver metastases eight years after the surgery. Eight children (36%) were found to carry MEN1 mutations, inherited n=5, de novo n=1, no data, n=2. Children with MEN1 had significantly higher number of pancreatic tumors compared to sporadic cases. All of them developed additional MEN1 symptoms during the following 2-13 years. In the five patients with inherited MEN1, seven family members had hitherto undiscovered MEN1 manifestations. Conclusions: In this large cohort of children with rare pediatric insulinomas, MEN1 syndrome and G2 tumors were frequent, as well as hitherto undiscovered MEN1 manifestations in family members. Our data emphasize the need of genetic testing in all children with insulinoma and their relatives, even in the absence of any other features, as well as the importance of a prolonged follow-up observation.

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. Different risk factors for neuro-developmental disorders were analysed by Mann-Whitney U test and Fisher's exact P test. Results: We identified 25 cases with GLUD1 mutations (12 males). Median age of presentation was 7 months (12 h-18 months). Hypoglycaemic seizures were the presenting feature in 24 (96%) cases. Twenty four cases responded to diazoxide and protein restriction whilst one patient underwent partial pancreatectomy. In total, 13 cases (52%) developed neurodevelopmental manifestations. Epilepsy (n = 9/25, 36%), learning difficulties (n = 8/25, 32%) and speech delay (n = 8/25, 32%) were the most common neurological manifestation. Median age of presentation for epilepsy was 12 months with generalised tonic-clonic seizures being the most common (n = 4/9, 44.4%) followed by absence seizures (n = 3/9, 33.3%). Early age of presentation (P = 0.02), diazoxide dose (P = 0.04) and a mutation in exon 11 or 12 (P = 0.01) were associated with neurological disorder. Conclusion: HI/HA syndrome is associated with wide spectrum of neurological disorders. These neurological manifestations were more frequent in cases with mutations affecting the GTP-binding site of GLUD1 in our cohort.

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 responsiveness was defined as the ability to maintain normoglycaemia without intravenous glucose. Macrosomia was defined as a birth weight ≥90th centile. SPSS v.27.1 was used for data analysis. RESULTS: A total of 34 patients (70.6% female, n = 24) with a mean age of 7.1 years (s.d. 6.4) were included. A total of 21 different heterozygous HNF4Amutations were identified in 29 patients (four novels). Four different previously described heterozygous HNF1A mutations were detected in five patients. Most (97.1%, n = 33) developed hypoglycaemia by day 2 of life. The mean birth weight was 3.8 kg (s.d. 0.8), with most infants macrosomic (n = 21, 61.8%). Diazoxide was commenced in 28 patients (82.3%); all responded. HH resolved in 20 patients (58.8%) following a median of 0.9 years (interquartile range (IQR): 0.2-6.8). Nine patients (n = 9, 26.5%) had developmental delay. Two patients developed Fanconi syndrome (p.Arg63Trp, HNF4A) and four had other renal or hepatic findings. Five (14.7%) developed MODY at a median of 11.0 years (IQR: 9.0-13.9). Of patients with inherited mutations (n = 25, 73.5%), a family history of diabetes was present in 22 (88.0%). CONCLUSIONS: We build on the knowledge of the natural history and pancreatic and extra-pancreatic phenotypes of HNF4A/HNF1Amutations and illustrate the heterogeneity of this condition.

The coincidence of two rare diseases with opposite metabolic phenotype: a child with congenital hyperinsulinism and Bloom syndrome.

OBJECTIVES: Congenital hyperinsulinism (CHI) is a group of rare genetic disorders characterized by insulin overproduction. CHI causes life-threatening hypoglycemia in neonates and infants. Bloom syndrome is a rare autosomal recessive disorder caused by mutations in the BLM gene resulting in genetic instability and an elevated rate of spontaneous sister chromatid exchanges. It leads to insulin resistance, early-onset diabetes, dyslipidemia, growth delay, immune deficiency and cancer predisposition. Recent studies demonstrate that the BLM gene is highly expressed in pancreatic islet cells and its mutations can alter the expression of other genes which are associated with apoptosis control and cell proliferation. CASE PRESENTATION: A 5-month-old female patient from consanguineous parents presented with drug-resistant CHI and dysmorphic features. Genetic testing revealed a homozygous mutation in the KCNJ11 gene and an additional homozygous mutation in the BLM gene. While 18F-DOPA PET scan images were consistent with a focal CHI form and intraoperative frozen-section histopathology was consistent with diffuse CHI form, postoperative histopathological examination revealed features of an atypical form. CONCLUSIONS: In our case, the patient carries two distinct diseases with opposite metabolic phenotypes.

[Continuous subcutaneous infusion of somatostatin analogues in the treatment of congenital hyperinsulinism].

BACKGROUND: Congenital hyperinsulinism (CHI) is a severe disease with a high risk of development of neurological complications due to persistent hypoglycemia. The use of an analog of somatostatin (octreotide) in patients with the resistance to the first-line drug allows to avoid surgical intervention. However, the octreotide is currently used in the form of frequent fractional injections due to the short duration of it’s effect. We present in this article our own experience of using octreotide in continuous subcutaneous infusion in pediatric patients in order to improve the quality of life. AIM To evaluate the efficiency and safety of the regime of continuous subcutaneous infusion of octreotide with the use of micro-dispensers (pumps) in children with diazoxide-resistant course of CHI. MATERIALS AND METHODS: An observational single-centre dynamic research was carried out on the basis of the Federal State Budgetary Institution «Endocrinology Research Centre» of the Ministry of Health of the Russian Federation. The study included pediatric patients with CHI and proven diazoxide-resistant course who were initially treated with octreotide in the form of intermittent subcutaneous injections. The researches compared the indicants of efficiency and safety of therapy on treatment of intermittent injections and after transfer to continuous subcutaneous infusion of the drug. The duration of each method of administration was at least 2 weeks. RESULTS: 16 patients took part in the research. The median for the total duration of octreotide usage in the examined patients was 3 months. According to the results of the work, the use of micro-dispensers for continuous subcutaneous administration of octreotide allowed to reduce the number of patients with episodes of hypoglycemia for more than 4 times (13/16 vs. 3/16); p=0,001). Also, there was a significant decrease in the number of patients with hyperglycemic episodes (4/16 vs. 0/16); p=0.000) and reduced dose of intravenous glucose (6.8 vs 5.2 mg/kg/min; p=0.042) as a result of continuous therapy, which indicates the advantages of smooth continuous administration comparing to single injections. We have not detected any significant side effects of the treatment. Elevated liver enzyme levels, dyspeptic symptoms and gallstone formation in some patients did not require cancellation of therapy. There were no hormonal disorders in the form of hypothyroidism and somatotropic hormone deficiency against the background of continuous octreotide infusion. CONCLUSIONS: Thus, the use of octreotide in patients with diazoxide-resistant course of СHI in continuous subcutaneous infusion using pumps has a number of advantages over the standard method of intermittent subcutaneous injection. This method of administration allows to achieve better glycemic control and reduce the risks from infusion therapy with highly concentrated glucose solutions, which undoubtedly improves the quality of life of patients.

[Transient hyperinsulinism in neonates].

Congenital hyperinsulinusm is rare disease characterized high secretion of insulin by pancreatic beta cells leading to the development of hypoglycemia. Persistent and transient forms of hyperinsulinism are distinguished. Transient hyperinsulinism are the most common cause of severe hypoglycemia in newborns. The etiology of this disease is not known. There are risk factors for the development of transient hyperinsulinism: asphyxia at birth, prematurity, maternal diabetes, low or large weight by gestation. Hypoglycemia with hyperinsulinism is severe. Therefore, early diagnosis and therapy especially during the neonatal period, are necessary.The article describes 3 clinical cases of transient hyperinsulinism in children with different gestational age and concomitant pathology. All children recevied insulinostatic therapy with diazoxide with a positive effect: euglycemia without glucose requirement . In all children, therapy was completed subsequently. At the time of publication of the article, the physical and psychomotor development of children is normal.

Hepatic glycogen synthase (GYS2) deficiency: seven novel patients and seven novel variants.

Glycogen storage disease type 0 (GSD 0) is an autosomal recessive disorder of glycogen metabolism caused by mutations in the GYS2 gene manifesting in infancy or early childhood and characterized by ketotic hypoglycemia after prolonged fasting, and postprandial hyperglycemia and hyperlactatemia. GSD 0 is a rare form of hepatic glycogen storage disease with less than 30 reported patients in the literature so far.DNA samples of 93 Russian patients with clinical diagnoses of hepatic GSDs were collected and analyzed by next-generation sequencing custom target panel and by direct sequencing. Seven new GSD 0 patients with variable phenotypes were found showing 10 variants. Seven variants are novel.We present seven new GSD 0 patients with variable phenotypes. Overall, 10 different mutant alleles of the GYS2 gene were found. Seven of them are novel: c.214delC, c.845delT, c.1644C>A, c.205T>A, c.929G>T, c.1169G>C and c.1703C>A. Three of the novel variants were annotated as pathogenic and likely pathogenic; four other variants have an uncertain significance.The current results expand the spectrum of known mutations in GYS2 and suggest that phenotypes of GSD 0 are more variable and less specific than the reported ones. SYNOPSIS: Seven new patients with glycogen storage disease type 0 were found using next-generation sequencing and seven novel variants of GYS2 gene were annotated.

18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism: a blinded evaluation.

PURPOSE: Focal congenital hyperinsulinism (CHI) is curable by surgery, which is why identification of the focal lesion is crucial. We aimed to determine the use of 18F-fluoro-dihydroxyphenylalanine (18F-DOPA) PET/CT vs. 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid-1-Nal3-octreotide (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. METHODS: PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUVmax) by two independent examiners, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. RESULTS: Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut-off-based evaluation: sensitivity (95% CI) of 1 (0.85-1); specificity of 0.96 (0.82-0.99). The optimal 18F-DOPA PET SUVmax ratio cut-off was 1.44 and the optimal 68Ga-DOTANOC PET SUVmax cut-off was 6.77 g/ml. The area under the receiver operating curve was 0.98 (0.93-1) for 18F-DOPA PET vs. 0.71 (0.43-0.95) for 68Ga-DOTANOC PET (p < 0.03). In patients subjected to surgery, localization of the focal lesion was correct in 91%, and 100%, by 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT, respectively. CONCLUSION: 18F-DOPA PET/CT was excellent in predicting focal CHI and superior compared to 68Ga-DOTANOC PET/CT. Further use of 68GA-DOTANOC PET/CT in predicting focal CHI is discouraged.

Both Low Blood Glucose and Insufficient Treatment Confer Risk of Neurodevelopmental Impairment in Congenital Hyperinsulinism: A Multinational Cohort Study.

BACKGROUND/AIMS: Congenital hyperinsulinism (CHI) is a heterogeneous disease most frequently caused by KATP-channel (ABCC8 and KCNJ11) mutations, with neonatal or later onset, variable severity, and with focal or diffuse pancreatic involvement as the two major histological types. CHI confers a high risk of neurological impairment; however, sparsely studied in larger patient series. We assessed the neurodevelopmental outcome in children with CHI at follow-up in a mixed international cohort. METHODS: In two hyperinsulinism expert centers, 75 CHI patients were included (Russian, n = 33, referred non-Scandinavian, treated in Denmark n = 27, Scandinavian, n = 15). Hospital files were reviewed. At follow-up, neurodevelopmental impairment and neurodevelopmental, cognitive and motor function scores were assessed. RESULTS: Median (range) age at follow-up was 3.7 years (3.3 months-18.2 years). Neurodevelopmental impairment was seen in 35 (47%). Impairment was associated with abnormal brain magnetic resonance imaging (MRI); odds ratio (OR) (95% CI) 15.0 (3.0-74.3), p = 0.001; lowest recorded blood glucose ≤1 mmol/L; OR 3.8 (1.3-11.3), p = 0.015, being non-Scandinavian patient, OR 3.8 (1.2-11.9), p = 0.023; and treatment delay from first symptom to expert center >5 days; OR 4.0 (1.0-16.6), trend p = 0.05. In multivariate analysis (n = 31) for early predictors with exclusion of brain MRI, treatment delay from first symptom to expert center >5 days conferred a significantly increased risk of neurodevelopment impairment, adjusted OR (aOR) 15.6 (1.6-146.7), p = 0.016, while lowest blood glucose ≤1 mmol/L had a trend toward increased risk, aOR 3.5 (1.1-14.3), p = 0.058. No associations for early vs. late disease onset, KATP-channel mutations, disease severity, focal vs. diffuse disease, or age at follow-up were seen in uni- or multivariate analysis. CONCLUSION: Not only very low blood glucose, but also insufficient treatment as expressed by delay until expert center hospitalization, increased the risk of neurodevelopmental impairment. This novel finding calls for improvements in spread of knowledge about CHI among health-care personnel and rapid contact with an expert CHI center on suspicion of CHI.

Idiopathic postprandial hyperinsulinaemic hypoglycaemia.

BACKGROUND: Idiopathic postprandial hyperinsulinaemic hypoglycaemia (PPHH) has rarely been reported in the paediatric age. The objective of this study was to describe the clinical characteristics, diagnosis and management in a group of children with PPHH. METHODS: Six children (three females) with a mean follow-up of 3.5±3.0 years at a single tertiary paediatric hospital. All had 24-h blood glucose monitoring, diagnostic fast and prolonged oral glucose tolerance test (OGTT). Follow-up included: 24-h blood glucose monitoring or continuous glucose monitoring system, prolonged OGTT and/or mixed meal (MM) test. RESULTS: Age at diagnosis ranged from 5.4 to 15.7 years and auxology parameters were within normal range in all subjects. All the children had a normal fasting tolerance for age. Prolonged OGTT demonstrated symptomatic hypoglycaemia after 120 min in all the patients with simultaneous detectable serum insulin concentration. Acarbose was tried in three patients, having a positive effect on glycaemic and symptom control, but due to side effects, only two patients continued acarbose in the long run. Diazoxide proved to be beneficial in one patient. The rest of the patients were managed with frequent feeds but despite this, prolonged OGTT/MM demonstrated on-going PPHH. CONCLUSIONS: Prolonged OGTT is necessary to diagnose PPHH in children. Acarbose is beneficial in children with PPHH, although not well tolerated. Patients managed exclusively on frequent feeds demonstrated persistent hypoglycaemia on OGTT. The underlying cause of the PPHH in these patients remains unknown.

Response of pure red cell aplasia to cyclophosphamide after failure of mycofenolate mofetil in a patient with polyglandular syndrome type I.

A 26-year-old female with the classic major and minor components of autoimmune polyglandular syndrome type 1 was diagnosed as having pure red cell aplasia. Treatment with 1.5 g/d mycofenolate mofetil for 3 months failed to restore erythroid production. Treatment with cyclosporine A produced a good partial response but led to renal toxicity and was therefore substituted with cyclophosphamide, which had a good partial effect and lasted for 18 months. The relapse of anemia was not observed during the 6-month follow-up period after the cessation of treatment.