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1.  Importance of Insulin Immunoassays in the Diagnosis of Factitious Hypoglycemia 
We report two cases emphasizing the importance of insulin assays for evaluation of hypoglycemia in diabetic patients. Case 1 was a 96/12-year-old female patient with type 1 diabetes mellitus and case 2 was a 1010/12-year-old male patient with DIDMOAD. Both patients were on a basal-bolus insulin regimen. Both were admitted because of persistent hypoglycemia. Analyses of serum samples obtained at the time of hypoglycemia initially showed low insulin and C-peptide levels. Recurrent episodes of unexplained hypoglycemia necessitated measurement of insulin levels by using different insulin assays, which revealed hyperinsulinemic hypoglycemia with low C-peptide levels, findings which confirmed a diagnosis of factitious hypoglycemia. Surreptitious administration of insulin should not be excluded in diabetic patients with hypoglycemia without taking into account the rate of cross-reactivity of insulin analogues with the insulin assay used.
PMCID: PMC4293663  PMID: 25541899
type 1 diabetes mellitus; DIDMOAD; factitious hypoglycemia; recurrent hypoglycemia; insulin assay
2.  Cathepsin K analysis in a pycnodysostosis cohort: demographic, genotypic and phenotypic features 
To characterize cathepsin K (CTSK) mutations in a group of patients with pycnodysostosis, who presented with either short stature or atypical fractures to pediatric endocrinology or dysmorphic features to pediatric genetics clinics.
Seven exons and exon/intron boundaries of CTSK gene for the children and their families were amplified with PCR and sequenced. Sixteen patients from 14 families with pycnodysostosis, presenting with typical dysmorphic features, short stature, frequent fractures and osteosclerosis, were included in the study.
We identified five missense mutations (M1I, I249T, L7P, D80Y and D169N), one nonsense mutation (R312X) and one 301 bp insertion in intron 7, which is revealed as Alu sequence; among them, only L7P and I249 were described previously. The mutations were homozygous in all cases, and the families mostly originated from the region where consanguineous marriage rate is the highest. Patients with M1I mutation had fractures, at younger ages than the other pycnodysostosis cases in our cohort which were most probably related to the severity of mutation, since M1I initiates the translation, and mutation might lead to the complete absence of the protein. The typical finding of pycnodysostosis, acroosteolysis, could not be detected in two patients, although other patients carrying the same mutations had acroosteolysis. Additionally, none of the previously described hot spot mutations were seen in our cohort; indeed, L7P and R312X were the most frequently detected mutations.
We described a large cohort of pycnodysostosis patients with genetic and phenotypic features, and, first Alu sequence insertion in pycnodysostosis.
PMCID: PMC4022088  PMID: 24767306
Cathepsin K; Pycnodysostosis; Fracture; Craniosynostosis; Arnold Chiari malformation
3.  Neonatal Seizure as a Manifestation of Unrecognized Maternal Hyperparathyroidism 
Maternal hypercalcemia suppresses parathyroid activity in the fetus resulting in impaired parathyroid responsiveness to hypocalcemia after birth. Resultant hypocalcemia may be severe and prolonged and rarely may lead to convulsions. Here, we present a newborn infant admitted to the pediatric emergency department at age two weeks with recurrent tonic convulsions due to asymptomatic maternal hyperparathyroidism and vitamin D deficiency. Physicians should be aware that undiagnosed maternal hyperparathyroidism can cause severe hypocalcemia in the newborn.
Conflict of interest:None declared.
PMCID: PMC3814538  PMID: 24072092
hypocalcemia; transient hypoparathyroidism; maternal hyperparathyroidism; maternal hypercalcemia
4.  Diabetes Care, Glycemic Control, Complications, and Concomitant Autoimmune Diseases in Children with Type 1 Diabetes in Turkey: A Multicenter Study 
Objective: Epidemiologic and clinical features of type 1 diabetes mellitus (T1DM) may show substantial differences among countries. The primary goal in the management of T1DM is to prevent micro- and macrovascular complications by achieving good glycemic control. The present study aimed to assess metabolic control, presence of concomitant autoimmune diseases, and of acute and long-term complications in patients diagnosed with T1DM during childhood and adolescence. The study also aimed to be a first step in the development of a national registry system for T1DM, in Turkey.
Methods: Based on hospital records, this cross-sectional, multicenter study included 1 032 patients with T1DM from 12 different centers in Turkey, in whom the diagnosis was established during childhood. Epidemiological and clinical characteristics of the patients were recorded. Metabolic control, diabetes care, complications, and concomitant autoimmune diseases were evaluated.
Results: Mean age, diabetes duration, and hemoglobin A1c level were 12.5±4.1 years, 4.7±3.2 years, and 8.5±1.6%, respectively. Acute complications noted in the past year included ketoacidosis in 5.2% of the patients and severe hypoglycemia in 4.9%. Chronic lymphocytic thyroiditis was noted in 12%, Graves’ disease in 0.1%, and celiac disease in 4.3% of the patients. Chronic complications including neuropathy, retinopathy, and persistent microalbuminuria were present in 2.6%, 1.4%, and 5.4% of the patients, respectively. Diabetic nephropathy was not present in any of the patients. Mean diabetes duration and age of patients with neuropathy, retinopathy and microalbuminuria were significantly different from the patients without these long-term complications (p<0.01). A significant difference was found between pubertal and prepubertal children in terms of persistent microalbuminuria and neuropathy (p=0.02 and p<0.001, respectively). Of the patients, 4.4% (n:38) were obese and 5% had short stature; 17.4% of the patients had dyslipidemia, and 14% of the dyslipidemic patients were obese.
Conclusions: Although the majority of the patients in the present study were using insulin analogues, poor glycemic control was common, and chronic complications were encountered.
Conflict of interest:None declared.
PMCID: PMC3628388  PMID: 23419424
type 1 diabetes; children; complications; Turkey
5.  A Case of Turner Syndrome with Concomitant Transient Hypogammaglobulinaemia of Infancy and Central Diabetes Insipidus 
Turner syndrome (TS) is a genetic disorder that affects development in females and is characterized by the complete or partial absence of the second sex chromosome, or monosomy X. TS is associated with abnormalities in lymphatic and skeletal development, in growth, and in gonadal function. Cardiac and renal malformations and a number of specific cognitive findings may also be encountered in these patients. An increased risk for hypothyroidism, sensorineural hearing loss, hypertension, and other problems has also been reported. We present the case of a patient with TS accompanied by transient hypogammaglobulinaemia of infancy (THI) and central diabetes insipidus, which we believe is the first reported TS patient with these concomitant disorders.
Conflict of interest:None declared.
PMCID: PMC3628396  PMID: 23419422
Turner syndrome; hypogammaglobulinaemia; central diabetes insipidus; mental retardation
6.  Height, Weight and Body Mass Index Percentiles of Children Aged 6-14 Years Living at Moderate Altitudes 
Objective: Individuals living at high altitudes are reported to have lower stature and also a smaller chest size in relation to their stature. Altitude-related hypobaric hypoxia is considered to be the major cause of these alterations in growth, but adverse socioeconomic and/or other environmental conditions may also have a role in poor growth performance. This study was undertaken to provide growth data on children and adolescents living in a moderate-altitude area in Turkey.
Methods: The dataset of an anthropometric study conducted among a population living in a city at an altitude of 2000 meters was analyzed. A total of 1638 children and adolescents (871 males and 767 females) aged between 6 and 14 years were included in this study. The LMS method was used in the analysis and percentile values corresponding to the 3rd, 5th, 10th, 15th, 25th, 50th, 75th, 85th, 90th, 95th and 97th percentiles for height, weight and body mass index (BMI) were estimated. The results were compared with the measurements of children and adolescents living in areas of lower altitude in Turkey.
Results: Starting at ages 0-10 years, height, weight and BMI values of children and adolescents of both genders living at an altitude of 2000 meters were noticeably lower than those reported for their counterparts living in areas of lower altitude in Turkey.
Conclusions: The higher values for height, weight and BMI in children living in low-altitude areas can be attributed to altitude effect, but socioeconomic and microclimate effects cannot be discarded and further studies are needed.
Conflict of interest:None declared.
PMCID: PMC3316457  PMID: 22394700
weight; height; body mass index; adolescents; mid altitude; percentiles
7.  Anogenital Measurements in Newborns 
PMCID: PMC3316465
Newborns; caliper; Anogenital distance
8.  Anogenital Distance in Turkish Newborns 
Objective: Anogenital distances are considered to be a sensitive indicator of external genitalia exposure to factors such as anti-androgens, and/or endocrine distruptors during the prenatal period. Exposure to such factors can lead to changes in the anogenital measurements (AGM) of newborn infants. These measurements can be used to predict masculinization of the external genitalia in healthy newborns. The goal of this study was to determine normal values for AGM in Turkish newborns of both genders.
Methods: One hundred fifteen female and 135 male term newborns with no congenital defects were included in this study. A well-trained observer measured the anogenital distance by using a sliding Caliper graduated in millimeters. Anogenital distance was measured from the center of the anus to the posterior convergence of the fourchette in females and from the center of the anus to the junction of the smooth perineal skin with the base of the scrotum in males.
Results: Anogenital distance in males and females was 23±0.6 mm and 10.3±0.2 mm, respectively. There were significant differences in anogenital distance values between male and female newborns (p<0.05).
Conclusion: The findings of this study provide data that can be used as reference standards with regard to AGM of the posterior genital structures in Turkish male and female newborns. These data will also serve in postnatal evaluations to determine the effects of prenatal exposures to factors affecting development of genitalia.
Conflict of interest:None declared.
PMCID: PMC3184512  PMID: 21911324
Anogenital distance; newborn; measurement
9.  Cystinosis Presenting with Findings of Bartter Syndrome 
A five-year-old boy was referred to our pediatric clinic for evaluation of failure to thrive, headache, intermittent high fever, restlessness, polyuria, and polydipsia. His weight and height measurements were under the 3rd percentile. Clinical findings consisted of frontal bossing, carious teeth, O-bain deformity of the lower extremities, and moderate dehydration. The presence of metabolic alkalosis, hypokalemia, hypochloremia, and high renin and aldosterone levels were suggestive of Bartter syndrome and a treatment regimen for Bartter syndrome was started. At follow-up, the polyuria and hyponatremia were found to persist. A reassessment of the patient revealed findings consistent with proximal renal tubular acidosis such as metabolic acidosis with a high urinary pH, proteinuria, aminoaciduria with phosphaturia and hypercalciuria. Based on the presence of parental consanguinity as well as polyuria, proteinuria, low tubular reabsorption of phosphorus, generalized aminoaciduria, light yellow skin and hair color, the probable diagnosis of cystinosis was established and was confirmed by slit-lamp examination of the cornea showing cystine crystal deposition. Our case is a good example demonstrating that development of metabolic alkalosis does not exclude cystinosis and that all findings of the patient should be thoroughly evaluated.
Conflict of interest:None declared.
PMCID: PMC3119438  PMID: 21750641
Cystinosis; bartter syndrome; metabolic alkalosis
10.  Nutritional Rickets 
Nutritional rickets (NR) is still the most common form of growing bone disease despite the efforts of health care providers to reduce the incidence of the disease. Today, it is well known that the etiology of NR ranges from isolated vitamin D deficiency (VDD) to isolated calcium deficiency. In Turkey, almost all NR cases result from VDD. Recent evidence suggests that in addition to its short− or long−term effects on skeletal development, VDD during infancy may predispose the patient to diseases such as diabetes mellitus, cancer and multiple sclerosis. Among the factors responsible for the high prevalence of VDD in developing countries and its resurgence in developed countries is limited sunshine exposure due to individuals’ spending more time indoors (watching television and working on computer) or avoiding sun exposure intentionally for fear of skin cancer. Traditional clothing (covering the entire body except the face and hands) further limits the exposure time to sunlight and, thus, decreases the endogenous synthesis of vitamin D. In Turkey, maternal VDD and exclusive breastfeeding without supplementation were reported to be the most prominent reasons leading to NR. The diagnosis of NR is established by a thorough history and physical examination and confirmed by laboratory evaluation. Recent reports draw attention to the supplemental doses of vitamin D required to achieve a serum 25−hydroxyvitamin D level of at least 20 ng/ml (50 nmol/l) − the serum concentration that is needed to optimize absorption of dietary calcium and to suppress excessive secretion of parathyroid hormone. This type of prevention will also reduce fracture risk as well as prevent long−term negative effect of vitamin D insufficiency.
Conflict of interest:None declared.
PMCID: PMC3005686  PMID: 21274312
Nutritional rickets; Vitamin D; calcium
12.  Circulating Insulin-like Growth Factor Binding Protein-4 (IGFBP-4) is not Regulated by Parathyroid Hormone and Vitamin D in vivo: Evidence from Children with Rickets 
Objective: Insulin-like growth factor binding protein-4 (IGFBP-4), inhibits IGF actions under a variety of experimental conditions. Parathyroid hormone (PTH), 1.25-hydroxy(OH)vitamin D, IGF-I, IGF-II and transforming growth factor (TGF)-b are the major regulators of IGFBP-4 production in vitro. However, little is known about the in vivo regulation of circulating IGFBP-4 in humans.
Methods: We measured serum concentrations of calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), PTH, vitamin D, IGF-I, IGFBP-3, and IGFBP-4 in infants (n=22) with nutritional rickets before and after treatment of rickets with vitamin D (300 000 U single dose po).
Results: The mean±SD age of the patients was 1.3±1.6 years (range 0.2-3). Serum Ca and P increased, whereas ALP and PTH decreased after treatment (Ca from 6.6±1.4 to 9.5±1.6 mg/dL, P from 3.9±1.4 to 5.4±0.8 mg/dL, ALP from 2590±2630 to 1072±776 IU/mL and PTH from 407±248 to 27.4±20.8 ng/dL, respectively). Vitamin D levels were low (7.8±2.5 ng/mL) and increased after treatment (18.1±4.0 ng/mL, p<0.001). Serum IGF-I and IGFBP-3 levels both increased after treatment (IGF-I: 13.5±12.2 vs. 23.7±14.2 ng/mL, p<0.001 and IGFBP-3: 1108±544 vs. 1652±424 ng/mL, p<0.001). However, serum IGFBP-4 levels did not change significantly after treatment (18.8±8.0 vs. 21.5±4.8 ng/mL). No correlation between PTH and IGF-I, IGFBP-3 or IGFBP-4 was detected. Significant correlations were observed between PTH and ALP (r=0.53, p<0.05), and between IGF-I and IGFBP-3 (r=0.46, p<0.05).
Conclusion: The results demonstrate that contrary to in vivo studies, circulating IGFBP-4 levels are not influenced by secondary hyperparathyroidism in vitamin D deficiency rickets since IGFBP-4 levels did not change after normalization of PTH with vitamin D treatment.
Conflict of interest:None declared.
PMCID: PMC3005664  PMID: 21274331
Vitamin D; rickets; IGF-I; IGFBP-3; IGFBP-4; PTH; Bone
13.  The Effect of Vitamin D Treatment on Serum Adiponectin Levels in Children with Vitamin D Deficiency Rickets 
Objective: Adiponectin and its receptors are known to be expressed in osteoblasts and may have important functions in normal bone cells. The aim of this study was to investigate the effect of vitamin D therapy on serum adiponectin levels in children with vitamin D deficiency rickets (VDDR).
Methods: 21 patients with VDDR were included in the study. Patients were treated with 300,000 U D3 (IM) and calcium lactate (50mg/kg/ day, PO, for 10 days). Anthropometric parameters and serum biochemical markers including calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), intact parathormone (iPTH), 25-hydroxyvitamin D (25(OH)D), and adiponectin levels were measured before and after one month of therapy.
Results: Weight and length, but not BMI, increased significantly after treatment. Serum 25(OH)D level increased significantly after treatment, while serum adiponectin level decreased (4.21±1.84 vs 52.73±17.63 ng/ml, p<0.000; 150.1±66.14 vs 84.29±9.06 mg/ml, p<0.000, respectively). No significant correlations were found between serum adiponectin and 25(OH)D levels before and after treatment or between delta adiponectin concentrations and delta 25(OH)D levels.
Conclusion: Serum adiponectin levels are increased in patients with VDDR, a finding which is probably related to increased osteoblastic activity.
Conflict of interest:None declared.
PMCID: PMC3005753  PMID: 21274306
treatment; Vitamin D; Adiponectin; rickets

Results 1-13 (13)