Arginine Vasopressin Deficiency in Children with Craniopharyngioma and Cerebral Germ Cell Tumour: Two Sides of the Same Coin. Clinical and Radiological features.

INTRODUCTION: Paediatric brain tumours in the sellar-suprasellar region (SSR) are often associated with arginine vasopressin peptide deficiency (AVPD), either at diagnosis caused by the tumour itself or during follow-up as consequence of treatments. The purpose of this research is to retrospectively describe the neuroradiological characteristics and the timing of AVPD development in a cohort of paediatric patients with craniopharyngioma (CP) or germ cell tumours (GCT). METHODS: We evaluated brain MRI at tumour diagnosis and at the onset of AVPD, as well as recorded clinical, endocrinological and histopathological data, treatments, and outcome. RESULTS: Seventy-two patients with AVPD were included: 46 CP (M: F=25:21) and 26 GCT (M: F=18:8). CPs were suprasellar (63%), sellar (4%) or both (33%). GCTs were suprasellar (65%), pineal (24%) or bifocal (11%). No statistically significant differences were noted in tumour size between CP and GCT. Posterior pituitary bright spot absence was reported at diagnosis or at follow-up (as surgery consequence) in all patients with AVPD, indicating that the absence of hyperintensity is a cardinal feature of AVPD. When measurable, pituitary stalk was thickened in most GCT patients (61.5%). At AVPD diagnosis in GCT, the mean age was 11.9 years; 18 (69%) patients had AVPD at the time of tumour diagnosis, 5 (19.3%) before the diagnosis with a latency of 24.4 months (range 4-48), and 3 (11.5%) during follow-up (mean 24 months, range 4-60) due to tumour recurrence. GCT patients presented with severe endocrinological manifestations (18/26), headache and vomiting (10/26), visual impairment (5/26) and behavioural changes with fatigue (1/26). In CP, the mean age at AVPD diagnosis was 10.3 years; 7 (15.2%) patients had AVPD at time of tumour diagnosis, 37 (80.5%) developed it shortly after neurosurgery and 2 patients (4.3%) after 2 and 4 months from surgery, respectively. Clinically, headache and visual abnormalities were the most frequent clinical symptoms at diagnosis of CP (39/46, 84.8%), with hydrocephalus (16/46, 35%) and displacement of optic chiasm (29/46, 63%) at the initial MRI. While the vast majority of CP patients (93%) received only surgery, all GCT patients received radiation therapy in addition to or instead of surgery. CONCLUSION: An early differential diagnosis in children with AVPD and brain tumours is supported by a good understanding of the clinical features and imaging findings. Expert follow-up is necessary.

Management of Central Diabetes Insipidus in Disabled Children with Diluted Oral Desmopressin Lyophilisate Formulation Administered Through Nasogastric Tube: A Retrospective Case Series.

BACKGROUND: Experience with nasogastric administration of oral DDAVP [desamino-D-arginine-8-vasopressin] lyophilisate (ODL) for central diabetes insipidus (CDI) in disabled children with swallowing coordination difficulties is limited. OBJECTIVE: We aimed to assess the safety and efficacy of nasogastric use of ODL in disabled children with CDI. Time to serum sodium normalisation was compared with that of children with normal intellect and CDI treated with sublingual DDAVP. METHODS: Clinical, laboratory and neuroimaging characteristics were evaluated for 12 disabled children with CDI treated with ODL through nasogastric tube at Dr Behcet Uz Children's Hospital, Turkey, between 2012 and 2022. RESULTS: Six boys and six girls with a mean (±SD) age of 43 (± 40) months were evaluated. These children (mean [±SD] weight standard deviation score [SDS] - 1.2 ± 1.7; mean [±SD] height SDS - 1.3 ± 1.4) presented with failure to thrive, irritability, prolonged fever, polyuria and hypernatraemia (mean serum sodium 162 [±3.6] mEq/L). At diagnosis, mean serum and urine osmolality were 321 (± 14) mOsm/kg and 105 (± 7.8) mOsm/kg, respectively. Arginine vasopressin (AVP) levels were undetectable (< 0.5 pmol/L) at diagnosis in all patients. Nasogastric tube administration of DDAVP lyophilisate (120 µg/tablet) dissolved in water (10 mL) was commenced at a dose of 1-5 µg/kg/day in two divided doses together with controlled water intake to avoid hyponatraemia. The frequency and dose of DDAVP were titrated based on urine output and serum sodium concentration. Serum sodium declined at a rate of 0.11 ± 0.03 mEq/L/h and reached normal range in a mean duration of 174 ± 46.5 h. Serum sodium declined faster in children with normal intellect and CDI treated with sublingual DDAVP (1.28 ± 0.39 mEq/L/h; p = 0.0003). Three disabled children needed rehospitalisation because of hypernatraemia due to unintentional DDAVP omission by caregivers. No episode of hyponatraemia was observed. Weight gain and growth were normal during the median (± interquartile range) follow-up duration of 32 ± 67 months. CONCLUSIONS: Nasogastric administration of oral DDAVP lyophilised formulation was safe and effective in the treatment of CDI in disabled children in this small retrospective series.

Endocrine manifestations of paediatric intracranial germ cell tumours: from diagnosis to long-term follow-up.

PURPOSE: We examined endocrine manifestations in a cohort of paediatric patients with IC-GCTs at diagnosis and during follow-up, integrating clinical, radiological, histopathological and laboratory data. METHODS: Diabetes insipidus (DI), growth hormone deficiency (GHD), hypothyroidism, adrenal insufficiency, precocious puberty (PP)/hypogonadism were diagnosed clinically and biochemically. The prevalence of endocrine manifestations was compared to survival rates. RESULTS: Our population included 55 children (37 males, 18 females) diagnosed with IC-GCT with a median follow-up of 78.9 months from diagnosis (range 0.5-249.9). At tumour diagnosis, 50.9% patients displayed endocrinopathies: among them, 85.7% were affected by DI, 57.1% central adrenal insufficiency, 50% central hypothyroidism, 28.5% GHD, 10.7% hypogonadotrophic hypogonadism, 10.7% PP. These patients presented predominantly with suprasellar germinoma. If not diagnosed previously, endocrine disorders arose 15.15 months (1.3-404.2) after end of treatment (EOT) in 16.4% patients. At least one endocrinopathy was identified in 67.3% of subjects at last follow-up visit, especially GHD and adrenal insufficiency. DI, hypothyroidism, and adrenal insufficiency occurred earlier than other abnormalities and frequently preceded tumour diagnosis. Subjects with and without endocrine manifestations who survived beyond 12 months after EOT did not show significant difference in overall survival and progression-free survival (p = 0.28 and p = 0.88, respectively). CONCLUSION: Endocrinopathies were common presenting symptoms in our population. If present at diagnosis, they often persisted hence after. The spectrum of endocrinopathies expanded during follow-up up to 33.7 years after EOT. Although they did not seem to affect survival rate in our cohort, close lifelong surveillance is mandatory to provide the best care for these patients.

Pituitary apoplexy in an adolescent male with macroprolactinoma presenting as middle cerebral artery territory infarction.

Pituitary apoplexy typically presents with acute headache, vomiting, visual disturbance, and confusion. Herein, we report a rare presentation of ischemic stroke due to pituitary apoplexy. A 16.5-year-old male presented with reduced Glasgow Coma Scale (GCS) score, slurred speech, right-sided hemiparesis, and bitemporal hemianopia. Magnetic resonance imaging of the brain showed a large hemorrhagic sellar/suprasellar mass and an area of cortical T2/FLAIR hyperintensity with corresponding diffusion restriction in the middle cerebral artery territory. Computed tomography (CT) intracranial angiogram showed luminal occlusion of the clinoid and ophthalmic segments of both internal carotid arteries (ICAs, left>right) due to mass pressure effect. Biochemical investigations confirmed hyperprolactinemia and multiple pituitary hormone deficiencies. Stress-dose hydrocortisone was commenced with cabergoline, followed by urgent endoscopic transsphenoidal debulking of the tumor (subsequent histology showing prolactinoma). Postoperative CT angiogram showed improved caliber of ICAs. Intensive neurorehabilitation was implemented and resulted in complete recovery of motor and cognitive deficits. At the last assessment (18.8 years), the patient remained on complete anterior pituitary hormone replacement without cabergoline. Pituitary apoplexy is a medical emergency requiring prompt recognition and treatment and should be suspected in patients presenting with sudden, severe headache; nausea; or visual disturbance and meningism. Ischemic stroke is a rare manifestation of pituitary apoplexy in the pediatric population.

Central Diabetes Insipidus in Children and Adolescents: Twenty-Six Year Experience from a Single Centre.

Introduction: Paediatric cohorts of central diabetes insipidus (CDI) have shown varying prevalence for different causes of CDI. The objective of this study was to determine the causes of CDI and long-term outcome in children and adolescents from a Tertiary Paediatric Endocrinology unit. Methods: The clinic database was searched to identify patients with CDI managed between 1993 and 2019. Relevant clinical information was collected from patient records. Results: A total of 138 CDI patients, median age 6 years (range <1-18) at presentation, were identified. Principal CDI aetiologies were craniopharyngioma (n = 44), acute central nervous system (CNS) insult (n = 33), germinoma (n = 15), postneurosurgery (indication other than craniopharyngioma and germinoma, n = 20), midline CNS malformation (n = 14), Langerhans cell histiocytosis (n = 5), and familial (n = 2). Idiopathic CDI in this cohort was infrequent (n = 5). Patients with CNS malformations/infections presented with CDI at a younger age compared to patients with CNS tumours (p < 0.0001). Five patients, initially presenting as idiopathic CDI, were subsequently diagnosed with germinoma after a median interval of 3.3 years. All patients with CDI related to craniopharyngioma and nearly all (87%) patients with CDI related to germinoma had concomitant GH, ACTH, and TSH deficiency. The majority of patients who manifested CDI due to acute CNS insult either deceased (30%) or had transient CDI (33.3%). Conclusion: Surgery for craniopharyngioma was the most common underlying aetiology of CDI with ubiquitous occurrence of panhypopituitarism in these patients. Manifestation of CDI in patients with acute CNS insult carries poor prognosis. We affirm that neuroimaging assessment in idiopathic CDI should be continued beyond 3 years from diagnosis as a significant number of patients exhibited progression of infundibular thickening 3 years post-CDI diagnosis.

IgG4-related hypophysitis in adolescence.

OBJECTIVES: IgG4-related hypophysitis is a novel clinical disease entity, which is typically seen in the sixth decade of life and is typically complicated by hypopituitarism. We describe an adolescent female with IgG4-related hypophysitis with normal pituitary function and summarize the relevant literature. CASE PRESENTATION: A 11.8-year-old girl presented with headache and left VI cranial nerve palsy. MRI brain identified an enlarged pituitary gland. Endocrine investigations revealed normal pituitary function. She underwent a transsphenoidal biopsy of the pituitary gland, and histological examination confirmed the diagnosis of IgG4-related hypophysitis. Serum IgG4 concentrations were normal and no evidence of other organ involvement was found. Although the patient tested strongly positive for TB on an interferon gamma release assay, pituitary biopsy was negative for granuloma formation and acid-fast bacilli (Ziehl-Neelson staining). IgG4-related hypophysitis was treated with oral prednisolone and mycophenolate-mofetil with a good response. CONCLUSIONS: We describe to the best of our knowledge, the youngest patient in the published literature with IgG4-related hypophysitis presenting without pituitary insufficiency. A literature review identified only five cases of IgG4-related hypophysitis in adolescence. Serum IgG4 concentrations were normal in all, except one of the adolescent patients reported so far, and appear unhelpful in diagnosis in this age group.

Prolactinoma in childhood and adolescence-Tumour size at presentation predicts management strategy: Single centre series and a systematic review and meta-analysis.

OBJECTIVE: To report the clinical presentation, management and outcomes of young patients with prolactinomas (<20 years) and conduct a systematic review and meta-analysis. PATIENTS AND DESIGN: Clinical, biochemical and radiological data (1996-2018) were collected from our centre. A systematic review and meta-analysis of published literature (1994-2019) on prolactinoma (age <20 years) were conducted. Both random and fixed effects meta-analysis were used to pool outcomes across studies. RESULTS 1 CASE SERIES: Twenty-two patients (14 females) were identified; median age at diagnosis 15.7 years (range 13-19); 12 patients (6 females) had a macroprolactinoma. Seven patients (macroprolactinoma-6) had associated pituitary hormone deficiencies at presentation. Five patients (4 males) underwent surgical resection due to poor response to cabergoline or apoplexy. Patients undergoing surgery had larger tumours (p < .02) and higher serum prolactin concentration (p < .005). All patients with macroprolactinoma >20 mm required surgical intervention. RESULTS 2 SYSTEMATIC REVIEW AND META-ANALYSIS: We selected 11 studies according to strict inclusion criteria describing 275 patients. Macroprolactinoma was more common in girls (78.7% [95% CI 70.5-85.9]) than boys and was more frequent than microprolactinoma (56.6% [95% CI 48.4-64.5]). In males, only 6/57 (10.5%) of tumours were microprolactinoma as compared to 102/198 (51.5%) microprolactinoma in females (risk difference -0.460; [95% CI -0.563 to -0.357]; p < .001). Surgery was first-line therapy in 18.9% patients, with another 15.4% requiring it as a second line (overall 31.3%). CONCLUSIONS: Macroprolactinoma, particularly if >20 mm, usually requires multimodal therapy including surgical intervention. While overall prolactinomas in <20 years age group are more common in females, the proportion of macroprolactinoma vs microprolactinoma is greater in males, particularly for large invasive tumours. Microprolactinoma is a rare diagnosis in adolescent males.

Acromesomelic Dysplasia, Type Maroteaux: Impact of Long-Term (8 Years) High-Dose Growth Hormone Treatment on Growth Velocity and Final Height in 2 Siblings.

INTRODUCTION: Acromesomelic dysplasia, type Maroteaux (AMDM) is a rare autosomal recessive skeletal dysplasia, characterized by severe dwarfism and disproportionate limb shortening. It results from loss-of-function NPR2 mutations affecting the C-type natriuretic peptide receptor. Resistance to growth hormone (GH) action has previously been suggested. We describe outcomes of 2 siblings with AMDM after prolonged high-dose GH treatment. PATIENTS/METHODS: Two siblings (Pt-A and Pt-B; consanguineous parents) presented in early childhood with severe disproportionate short stature and radiological features of AMDM. Subsequent genetic testing identified a novel homozygous NPR2 mutation. GH provocation testing showed relatively high GH levels. Serum insulin-like growth factor 1 (IGF-1) was ∼2 SD below age/sex-specific mean. High-dose GH (0.075 mg/kg/day) was started. Pre-GH height velocities were 3.7 (Pt-A) and 4.5 (Pt-B) cm/year. GH dose was adjusted to sustain serum IGF-1 towards +3 SDS for age/sex. Annualized height velocities for first 3 years on GH were 7.0, 5.4, and 4.7 cm/year for patient A and 9.4, 8.0, and 5.9 cm/year for patient B. Height gain during puberty was 10.6 (Pt-A) and 5.9 (Pt-B) cm. Final heights after 8.5 years of GH treatment were 130.5 cm (-6.57 SDS, Pt-A) and 134 cm (-4.58 SDS, Pt-B). CONCLUSIONS: To the best of our knowledge, this is the first report of final height in patients with AMDM after long-term GH treatment. Our results confirm the finding of relative GH resistance in AMDM, which when overcome with high-dose GH treatment resulted in improved height SDS during childhood and adolescence and associated quality of life. The final height of our patients was significantly higher than average reported final height (120 cm) of AMDM patients.

Xq27.1 Duplication Encompassing SOX3: Variable Phenotype and Smallest Duplication Associated with Hypopituitarism to Date - A Large Case Series of Unrelated Patients and a Literature Review.

BACKGROUND: Xq27.1 duplication encompassing SOX3 has been implicated in the aetiology of X-linked hypopituitarism associated with intellectual disability and neural tube defects. We describe the largest case series to date of 5 unrelated patients with SOX3 duplication with a variable clinical phenotype, including the smallest reported SOX3 duplication. CASE REPORTS: Five male patients who presented with congenital hypopituitarism (CH) were identified to have Xq27.1 duplication encompassing SOX3. The size of the duplication ranged from 323.8 kb to 11 Mb. The duplication was maternally inherited or de novo in 2 patients each (and of unknown inheritance in 1 patient). The age at presentation was variable. Three patients had multiple pituitary hormone deficiencies, whereas 2 patients had isolated growth hormone deficiency. All patients had micropenis and/or small undescended testes. Structural pituitary and/or other midline cranial abnormalities (callosal hypogenesis/absence of the septum pellucidum) were present in all patients. Two patients had a neural tube defect in addition to CH. CONCLUSIONS: This is the largest series reported to date of unrelated patients with CH in association with Xq27.1 duplication encompassing SOX3. The clinical phenotype is variable, which may be due to genetic redundancy or other unknown aetiological factors. We have expanded the phenotypic spectrum through description of the smallest Xq27.1 duplication (323.8 kb) with CH reported to date, as well as a second family with CH and a neural tube defect.

Idiopathic gonadotropin-independent precocious puberty - is regular surveillance required?

Context Germ cell tumours (GCTs) secreting ß-human chorionic gonadotropin (ß-HCG) are a rare cause of gonadotropin-independent precocious puberty (GIPP). Case description A 5.7-year-old boy presented with GIPP. Investigations to elucidate the underlying cause revealed elevated serum ß-HCG. Ultrasound of the abdomen and testes, urine steroid profile, bone isotope scan, and sequencing of the luteinizing hormone receptor gene (LHCGR) were normal. Despite paired serum and cerebrospinal fluid ß-HCG measurement suggesting local (brain) ß-HCG production, repeated magnetic resonance imaging (MRI) of the brain as well as MRI of the mediastinum did not identify a tumour source of persistently elevated serum ß-HCG. Treatment with cyproterone acetate and spironolactone was unsuccessful. Increase in testicular volumes prompted the addition of a gonadotropin releasing hormone (GnRH) analogue. Due to progressing virilisation and skeletal maturation, treatment was changed to a combination of anastrozole and bicalutamide at the age of 7 years. One year later, serum ß-HCG and testosterone concentrations spontaneously normalised followed by reductions in the height velocity, skeletal maturation and virilisation. The proband achieved his genetic height potential. No medication side effects were observed. The patient subsequently presented with non-secreting pineal GCT at 14 years, 8½ years after his initial presentation with GIPP. Conclusions Our case highlights that GIPP with no definite underlying aetiology at diagnosis should be considered as a prodrome for GCTs, and regular radiological surveillance for earlier tumour identification is warranted. To the best of our knowledge, our case is the first reported case of the use of anastrozole and bicalutamide in the setting of idiopathic GIPP. The good height outcome in our case warrants the trial of anastrozole and bicalutamide in similar cases.

Clinical characteristics and molecular genetic analysis of 22 patients with neonatal diabetes from the South-Eastern region of Turkey: predominance of non-KATP channel mutations.

BACKGROUND: Neonatal diabetes mellitus (NDM) is a rare form of monogenic diabetes and usually presents in the first 6 months of life. We aimed to describe the clinical characteristics and molecular genetics of a large Turkish cohort of NDM patients from a single centre and estimate an annual incidence rate of NDM in South-Eastern Anatolian region of Turkey. DESIGN AND METHODS: NDM patients presenting to Diyarbakir Children State Hospital between 2010 and 2013, and patients under follow-up with presumed type 1 diabetes mellitus, with onset before 6 months of age were recruited. Molecular genetic analysis was performed. RESULTS: Twenty-two patients (59% males) were diagnosed with NDM (TNDM-5; PNDM-17). Molecular genetic analysis identified a mutation in 20 (95%) patients who had undergone a mutation analysis. In transient neonatal diabetes (TNDM) patients, the genetic cause included chromosome 6q24 abnormalities (n=3), ABCC8 (n=1) and homozygous INS (n=1). In permanent neonatal diabetes (PNDM) patients, homozygous GCK (n=6), EIF2AK3 (n=3), PTF1A (n=3), and INS (n=1) and heterozygous KCNJ11 (n=2) mutations were identified. Pancreatic exocrine dysfunction was observed in patients with mutations in the distal PTF1A enhancer. Both patients with a KCNJ11 mutation responded to oral sulphonylurea. A variable phenotype was associated with the homozygous c.-331C>A INS mutation, which was identified in both a PNDM and TNDM patient. The annual incidence of PNDM in South-East Anatolian region of Turkey was one in 48 000 live births. CONCLUSIONS: Homozygous mutations in GCK, EIF2AK3 and the distal enhancer region of PTF1A were the commonest causes of NDM in our cohort. The high rate of detection of a mutation likely reflects the contribution of new genetic techniques (targeted next-generation sequencing) and increased consanguinity within our cohort.

Sirolimus therapy in a patient with severe hyperinsulinaemic hypoglycaemia due to a compound heterozygous ABCC8 gene mutation.

INTRODUCTION: Hyperinsulinaemic hypoglycaemia (HH) is the most common cause of severe and persistent hypoglycaemia in neonates. The treatment of severe diazoxide unresponsive HH involves near total pancreatectomy. Mammalian target of rapamycin (mTOR) is a protein kinase that regulates cellular proliferation. mTOR inhibitors are used in cancer patients and recently found to be effective in the treatment of insulinoma and HH patients. CASE: A 36 weeks large for gestational age neonate presented with severe hypoglycaemia on day 1 of life. The hypoglycaemia screen confirmed HH and genetic testing revealed compound heterozygous ABCC8 mutation, confirming diffuse disease. He was unresponsive to the maximal dose of diazoxide (15 mg/kg/day), hence needed treatment with higher concentration of intravenous glucose (25 mg/kg/min), intravenous glucagon and subcutaneous octreotide (30 µg/kg/day) infusions to maintain normoglycaemia. Sirolimus, a mTOR inhibitor, was commenced at 9 weeks of age following which he showed a marked improvement in his glycaemic control. After 4 weeks of sirolimus therapy, he was discharged home on subcutaneous octreotide injection (20 µg/kg/day) and oral sirolimus, thereby avoiding the need for a near total pancreatectomy. CONCLUSION: We report the first case of compound heterozygous ABCC8 mutation causing severe diffuse HH that responded to therapy with a mTOR inhibitor.

Familial isolated growth hormone deficiency due to a novel homozygous missense mutation in the growth hormone releasing hormone receptor gene: clinical presentation with hypoglycemia.

CONTEXT: Mutations in the growth hormone releasing hormone receptor (GHRHR) gene are a relatively rare cause of isolated growth hormone deficiency (IGHD). OBJECTIVE: This study aimed to understand the biochemical basis of hypoglycemia in the index case and the molecular basis of severe short stature in a large consanguineous family with IGHD. PATIENTS AND METHODS: The index case presented with a hypoglycemic convulsion, following which eight members in two related consanguineous Turkish families were identified with IGHD. Homozygosity mapping identified the homozygous regions shared only among the affected individuals. Sanger sequencing of GHRHR, which resided in the shared homozygous region, was performed. In silico analysis of the pathogenic GHRHR variant was performed. RESULTS: The clinical presentation and hormonal analysis confirmed GH deficiency in all affected individuals. Magnetic resonance imaging scan of the pituitary gland showed anterior pituitary hypoplasia in five affected individuals in which the youngest was only 0.4 years old, but with normal pituitary size in three affected individuals. Homozygosity mapping showed two large homozygous regions on chromosome 7 shared only among affected individuals. Sanger sequencing of GHRHR gene present in one of these shared regions identified a novel homozygous missense mutation (p.C64G) segregating with the disease phenotype. In silico analysis predicted the mutation to be deleterious and disease causing. CONCLUSIONS: We describe a large consanguineous Turkish kindred with IGHD due to a novel homozygous missense GHRHR mutation. This is the first description of presentation with hypoglycemia and the earliest reported occurrence of anterior pituitary hypoplasia in patients with GHRHR mutation.

Clinical and histological heterogeneity of congenital hyperinsulinism due to paternally inherited heterozygous ABCC8/KCNJ11 mutations.

CONTEXT: Congenital hyperinsulinism (CHI) has two main histological types: diffuse and focal. Heterozygous paternally inherited ABCC8/KCNJ11 mutations (depending upon whether recessive or dominant acting and occurrence of somatic maternal allele loss) can give rise to either phenotype. However, the relative proportion of these two phenotypes in a large cohort of CHI patients due to paternally inherited heterozygous ABCC8/KCNJ11 mutations has not been reported. OBJECTIVE: The purpose of this study is to highlight the variable clinical phenotype and to characterise the distribution of diffuse and focal disease in a large cohort of CHI patients due to paternally inherited heterozygous ABCC8/KCNJ11 mutations. DESIGN: A retrospective chart review of the CHI patients due to heterozygous paternally inherited ABCC8/KCNJ11 mutations from 2000 to 2013 was conducted. RESULTS: Paternally inherited heterozygous ABCC8/KCNJ11 mutations were identified in 53 CHI patients. Of these, 18 (34%) either responded to diazoxide or resolved spontaneously. Fluorine-18 l-3, 4-dihydroxyphenylalanine positron emission tomography computerised tomography 18F DOPA-PET CT) scanning in 3/18 children showed diffuse disease. The remaining 35 (66%) diazoxide-unresponsive children either had pancreatic venous sampling (n=8) or 18F DOPA-PET CT (n=27). Diffuse, indeterminate and focal disease was identified in 13, 1 and 21 patients respectively. Two patients with suspected diffuse disease were identified to have focal disease on histology. CONCLUSIONS: Paternally inherited heterozygous ABCC8/KCNJ11 mutations can manifest as a wide spectrum of CHI with variable 18F DOPA-PET CT/histological findings and clinical outcomes. Focal disease was histologically confirmed in 24/53 (45%) of CHI patients with paternally inherited heterozygous ABCC8/KCNJ11 mutations.

Long-term follow-up of children with congenital hyperinsulinism on octreotide therapy.

CONTEXT: Octreotide, a somatostatin analog, is commonly used in diazoxide unresponsive congenital hyperinsulinism (CHI) patients as a second-line therapy. OBJECTIVE: The aims of this study were to evaluate the dose range, side effects, and long-term follow-up of octreotide therapy in a large cohort of CHI patients. SETTING: The study was conducted at an international referral center for the management of CHI. PATIENTS: Twenty-eight (17 males) diazoxide unresponsive CHI patients (15 biallelic and 10 monoallelic ATP sensitive potassium channel mutation) managed with daily multidose octreotide therapy between 2001 and 2013 participated in the study. MAIN OUTCOME MEASURES: Regular follow-up of auxology, growth factors (serum IGF-1 and IGF binding protein 3 levels), thyroid functions, liver function tests, and hepatobiliary ultrasonography were measured. RESULTS: The median age of CHI diagnosis was 1 week (range 1-80 wk). The mean (±SD) dose of octreotide required was 17.8 (±7.5) µg/kg · d (range 7.5-30 µg/kg · d). The mean (±SD) duration of follow-up on octreotide therapy was 52.4 (±33.8) months (range 6 mo to 9.5 y). Elevation of liver enzymes was the most prevalent side effect (n = 13; 46.4%), which resolved spontaneously. Gallbladder pathology was detected in nine patients (32%). Mean (±SD) duration of octreotide therapy before the development of gallbladder pathology was 4.3 (±4.6 mo), whereas 19 patients were free of gallstones after a follow-up of 53.6 ± 32.9 months on octreotide therapy. There was no relationship between the dose or the duration of octreotide therapy and development of gallbladder pathology or liver dysfunction. CONCLUSIONS: Transient elevation of liver enzymes and asymptomatic gallbladder pathology were the most prevalent long-term side effects of octreotide therapy. There was no correlation between the dose or the duration of octreotide therapy and development of liver dysfunction and gallbladder pathology.

Pancreatic endocrine and exocrine function in children following near-total pancreatectomy for diffuse congenital hyperinsulinism.

CONTEXT: Congenital hyperinsulinism (CHI), the commonest cause of persistent hypoglycaemia, has two main histological subtypes: diffuse and focal. Diffuse CHI, if medically unresponsive, is managed with near-total pancreatectomy. Post-pancreatectomy, in addition to persistent hypoglycaemia, there is a very high risk of diabetes mellitus and pancreatic exocrine insufficiency. SETTING: International referral centre for the management of CHI. PATIENTS: Medically unresponsive diffuse CHI patients managed with near-total pancreatectomy between 1994 and 2012. INTERVENTION: Near-total pancreatectomy. MAIN OUTCOME MEASURES: Persistent hypoglycaemia post near-total pancreatectomy, insulin-dependent diabetes mellitus, clinical and biochemical (faecal elastase 1) pancreatic exocrine insufficiency. RESULTS: Of more than 300 patients with CHI managed during this time period, 45 children had medically unresponsive diffuse disease and were managed with near-total pancreatectomy. After near-total pancreatectomy, 60% of children had persistent hypoglycaemia requiring medical interventions. The incidence of insulin dependent diabetes mellitus was 96% at 11 years after surgery. Thirty-two patients (72%) had biochemical evidence of severe pancreatic exocrine insufficiency (Faecal elastase 1<100 µg/g). Clinical exocrine insufficiency was observed in 22 (49%) patients. No statistically significant difference in weight and height standard deviation score (SDS) was found between untreated subclinical pancreatic exocrine insufficiency patients and treated clinical pancreatic exocrine insufficiency patients. CONCLUSIONS: The outcome of diffuse CHI patients after near-total pancreatectomy is very unsatisfactory. The incidence of persistent hypoglycaemia and insulin-dependent diabetes mellitus is very high. The presence of clinical rather than biochemical pancreatic exocrine insufficiency should inform decisions about pancreatic enzyme supplementation.

Clinical characteristics and phenotype-genotype analysis in Turkish patients with congenital hyperinsulinism; predominance of recessive KATP channel mutations.

OBJECTIVE: Congenital hyperinsulinism (CHI) is the commonest cause of hyperinsulinaemic hypoglycaemia in the neonatal, infancy and childhood periods. Its clinical presentation, histology and underlying molecular biology are extremely heterogeneous. The aim of this study was to describe the clinical characteristics, analyse the genotype-phenotype correlations and describe the treatment outcome of Turkish CHI patients. DESIGN AND METHODS: A total of 35 patients with CHI were retrospectively recruited from four large paediatric endocrine centres in Turkey. Detailed clinical, biochemical and genotype information was collected. RESULTS: Diazoxide unresponsiveness was observed in nearly half of the patients (n=17; 48.5%). Among diazoxide-unresponsive patients, mutations in ABCC8/KCNJ11 were identified in 16 (94%) patients. Among diazoxide-responsive patients (n=18), mutations were identified in two patients (11%). Genotype-phenotype correlation revealed that mutations in ABCC8/KCNJ11 were associated with an increased birth weight and early age of presentation. Five patients had p.L1171fs (c.3512del) ABCC8 mutations, suggestive of a founder effect. The rate of detection of a pathogenic mutation was higher in consanguineous families compared with non-consanguineous families (87.5 vs 21%; P<0.0001).Among the diazoxide-unresponsive group, ten patients were medically managed with octreotide therapy and carbohydrate-rich feeds and six patients underwent subtotal pancreatectomy. There was a high incidence of developmental delay and cerebral palsy among diazoxide-unresponsive patients. CONCLUSIONS: This is the largest study to report genotype-phenotype correlations among Turkish patients with CHI. Mutations in ABCC8 and KCNJ11 are the commonest causes of CHI in Turkish patients (48.6%). There is a higher likelihood of genetic diagnosis in patients with early age of presentation, higher birth weight and from consanguineous pedigrees.

Activating AKT2 mutation: hypoinsulinemic hypoketotic hypoglycemia.

BACKGROUND: Hyperinsulinemic hypoglycemia (HH), characterized by unregulated insulin secretion, is an important cause of persistent and severe hypoglycemia. The biochemical picture of HH is hypoketotic hypo-fatty-acidemic hypoglycemia along with elevated serum insulin. Not infrequently, serum insulin might be undetectable in HH despite the presence of evidence of insulin action (suppressed ketogenesis and lipolysis). However, autonomous activity of the downstream insulin signaling pathway without the presence of the ligand (insulin) will give rise to the same clinical and biochemical picture, apart from undetectable serum insulin/C-peptide. AKT2, a serine/threonine protein kinase, is involved downstream to the insulin receptor in mediating the physiological effects of insulin. AIM: We describe the second report of an activating AKT2 mutation leading to hypoinsulinemic hypoketotic hypoglycemia. PATIENTS AND METHODS: The proband presented with hemihypertrophy and symptomatic hypoglycemia. Investigations confirmed evidence of insulin action, despite absence of detectable serum insulin on multiple occasions. Molecular genetic testing for common causes of HH (ABCC8, KCNJ11, and GLUD1) was negative. Sequencing of AKT2 identified a de novo mosaic c.49G→A (p.E17K) mutation, consistent with the clinical and biochemical phenotype. CONCLUSIONS: This is the second report of an activating AKT2 mutation leading to hypoinsulinemic hypoketotic hypo-fatty-acidemic hypoglycemia. In patients presenting a clinical and biochemical picture of HH with undetectable serum insulin, consideration of autonomous activation of the downstream insulin signaling pathway should be made.