Huseyin Demirbilek

Hashimoto's thyroiditis in children and adolescents: A retrospective study on clinical, epidemiological and laboratory properties of the disease

UNLABELLED Hashimotos thyroiditis (HT) is the most common cause of goiter and acquired hypothyroidism in children and adolescents in iodine replete areas. To find out the clinical, epidemiological and laboratory characteristics of the disease in childhood, we reviewed files of 162 children and adolescents with HT followed in the Department of Pediatric Endocrinology, Hacettepe University Faculty of Medicine. RESULTS Female patients constituted 86.4% (n = 140) of all patients with a female:male ratio of 6.4. Mean age at diagnosis was 11.4 +/- 2.97 years (age range 4.4-16.5 years). At the time of diagnosis 43.2% of the patients (n = 70) were euthyroid, 24.1% (n = 39) had subclinical hypothyroidism, 21% (n = 34) had overt hypothyroidism, and 8.6% (n = 14) had overt and 3.1% (n = 5) subclinical hyperthyroidism. CONCLUSIONS Autoimmune thyroiditis is more frequent in females, and increases in frequency over age during childhood and adolescence. At the time of diagnosis, frequency of overt and subclinical hypothyroidism is similar to that of euthyroid goiter.

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.

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.

Distribution of gene mutations associated with familial normosmic idiopathic hypogonadotropic hypogonadism.

Objective: Normosmic idiopathic hypogonadotropic hypogonadism (nIHH) is characterized by failure of initiation or maintenance of puberty due to insufficient gonadotropin release, which is not associated with anosmia/hyposmia. The objective of this study was to determine the distribution of causative mutations in a hereditary form of nIHH. Methods: In this prospective collaborative study, 22 families with more than one affected individual (i.e. multiplex families) with nIHH were recruited and screened for genes known or suspected to be strong candidates for nIHH. Results: Mutations were identified in five genes (GNRHR, TACR3, TAC3, KISS1R, and KISS1) in 77% of families with autosomal recessively inherited nIHH. GNRHR and TACR3 mutations were the most common two causative mutations occurring with about equal frequency. Conclusions: Mutations in these five genes account for about three quarters of the causative mutations in nIHH families with more than one affected individual. This frequency is significantly greater than the previously reported rates in all inclusive (familial plus sporadic) cohorts. GNRHR and TACR3 should be the first two genes to be screened for diagnostic purposes. Identification of causative mutations in the remaining families will shed light on the regulation of puberty. Conflict of interest:None declared.

Persistent hyperinsulinaemic hypoglycaemia in infancy.

Persistent hyperinsulinaemic hypoglycaemia in infancy (PHHI) is a heterogeneous condition characterised by unregulated insulin secretion in response to a low blood glucose level. It is the most common cause of severe and persistent hypoglycaemia in neonates. It is extremely important to recognise this condition early and institute appropriate management to prevent significant brain injury leading to complications like epilepsy, cerebral palsy and neurological impairment. Histologically, PHHI is divided mainly into three types-diffuse, focal and atypical disease. Fluorine-18-l-3,4-dihydroxyphenylalanine positron emission tomography (18F-DOPA-PET/CT) scan allows differentiation between diffuse and focal diseases. The diffuse form is inherited in an autosomal recessive (or dominant) manner whereas the focal form is sporadic in inheritance and is localised to a small region of the pancreas. The molecular basis of PHHI involves defects in key genes (ABCC8, KCNJ11, GCK, SLC16A1, HADH, UCP2, HNF4A and GLUD1) that regulate insulin secretion. Focal lesions are cured by lesionectomy whereas diffuse disease (unresponsive to medical therapy) will require a near-total pancreatectomy with a risk of developing diabetes mellitus and pancreatic exocrine insufficiency. Open surgery is the traditional approach to pancreatic resection. However, recent advances in laparoscopic surgery have led to laparoscopic near-total pancreatectomy for diffuse lesions and laparoscopic distal pancreatectomy for focal lesions distal to the head of the pancreas.

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.

Hypophosphatasia Presenting with Pyridoxine-Responsive Seizures, Hypercalcemia, and Pseudotumor Cerebri: Case Report

Hypophosphatasia (HPP) is an inborn error of metabolism characterized by defective bone mineralization caused by a deficiency in alkaline phosphatase (ALP) activity due to mutations in the tissue-nonspecific ALP (TNALP) gene. The clinical expression of the disease is variable. Six forms of HPP are identified according to age at presentation and clinical features. Patients with the infantile form are normal at birth. First symptoms appear within the first 6 months of life. Along with skeletal findings, HPP patients may present with hypercalcemia, seizures, pseudotumor cerebri, and pulmonary insufficiency. Seizures in HPP are refractory to conventional antiepileptic drugs, but are responsive to pyridoxine. Herein, we report a case of HPP who presented with pyridoxine-responsive seizures in the early neonatal period and was found to have hypercalcemia, skeletal demineralization and increased intracranial pressure. Key words: Hypophosphatasia, pyridoxine-responsive seizures, bisphosphonates, alkaline phosphatase, bone resorption, hypercalcemia Conflict of interest:None declared.

Incidence of type 1 diabetes mellitus in Turkish children from the southeastern region of the country: a regional report.

Objective: Variability in the incidence of type 1 diabetes mellitus (T1DM) related to geographical region, ethnic background, gender, and age indicates a need for further epidemiological studies. To date, there are no reported studies on the incidence of T1DM in the pediatric age group from the Southeastern region of Turkey. To define the incidence, demographic and clinical characteristics of T1DM in children 0-14 years of age in Diyarbakir, one of the largest cities in the Southeast region of Turkey. Methods: Hospital files of patients with the diagnosis of T1DM were reviewed. Data of all patients diagnosed between 1 June 2010 and 31 May 2011 were evaluated. Population data on the 0-14 age group were obtained from the Turkish Statistical Institute (TSI) reports. Results: From a total of 41 T1DM patients, 24 (58.5%) were female (male: 41.5%) with a male/female ratio of 1.4. The overall annual incidence of T1DM was 7.2/105, being 8.7/105 in females and 5.7/105 in males. The peak incidence was found to occur at age 5-9 years in the girls and 10-14 years in the boys. Mean age at diagnosis was 8.1±3.8 years. Rate of presentation with diabetic ketoacidosis was 65.9%. Patients applied most frequently in spring and winter months. Conclusions: In this first T1DM incidence study on the pediatric age group in Diyarbakir, Turkey, T1DM incidence was found to be similar to that in countries with low-middle incidence. Conflict of interest:None declared.

Evaluation of serum kisspeptin levels in girls in the diagnosis of central precocious puberty and in the assessment of pubertal suppression

Abstract Background: Onset of puberty is dependent on pulsatile secretion of gonadotropin releasing hormone (GnRH). The kisspeptin-GPR54 signaling system has a considerable role in GnRH physiology and induction of puberty. Objectives: To evaluate kisspeptin levels in girls with central precocious puberty (CPP) at the time of the diagnosis and during follow-up, to determine whether or not kisspeptin may serve as a marker for diagnosis and follow-up of CPP. Patients and methods: Kisspeptin levels of 28 girls with CPP were measured at the time of diagnosis and repeated at the 6th month of therapy after complete pubertal suppression and compared to kisspeptin levels of 13 age-matched prepubertal controls. Results: Kisspeptin levels of girls with CPP (10.2±2.6 pg/mL) were higher than those in controls (8.6±1.5 pg/mL (p<0.019). There was a significant decline in the kisspeptin levels (7.3±1.3 pg/mL) of girls with CPP after pubertal suppression (p<0.0001). Conclusion: These findings suggest that kisspeptin levels can be used as corroborative evidence for diagnosis of CPP and a valuable parameter for monitoring treatment efficacy.

17beta-hydroxysteroid dehydrogenase type 3 deficiency as a result of a homozygous 7 base pair deletion in 17betaHSD3 gene.

Abstract 17-β-Hydroxysteroid dehydrogenase type 3 (17βHSD-3) converts Δ4 androstenedione (A) to testosterone (T) in the testes. This enzyme plays a key role in androgen synthesis and it is essential for normal fetal development of male genitalia. 17βHSD-3 deficiency is a rare cause of 46,XY disorders of sexual development. Here, we report a 16-year-old 46,XY patient with 17βHSD-3 deficiency raised as a female and significantly virilized in puberty. A homozygous 7 base pair deletion on exon 10 was determined in HSD17B3 gene (c.777-783del_GATAACC). Our patient had one of the very rare mutations, which was previously unencountered in Turkish patients with 17βHSD type 3, and she is the second reported case with this deletion.