This article explores the basic development and pathophysiology of the thyroid gland. New factors in the normal development of the thyroid in the neonate are mentioned. The incidence of congenital hypothyroidism continues to increase. We describe congenital hypothyroidism, its possible etiologies, treatment and outcomes. We explore hypothyroxinanemia in pre-term neonates and the risk/benefit of prophylactic thyroid hormone replacement. We discuss the late rise of thyrotropin (TSH) in ill infants and those with very low birth weight. Ill infants or those born premature should have their thyroid function tests routinely monitored. On the occasion of borderline thyroid function test results, TRH testing can be useful in identifying those infants with either persistent or transient hypothyroidism. TRH testing is also helpful in identifying those patients with secondary hypothyroidism. With the early identification and prompt and proper treatment, neonates with congenital hypothyroidism, transient or persistent, should have positive long-term outcomes.

Objective: Childhood obesity is associated with an increased risk for insulin resistance. The underlying mechanism for the physiological increase in insulin levels in puberty is not clearly understood. The aim of the present study was to determine the cut-off values for homeostasis model assessment for insulin resistance (HOMA-IR) in obese children and adolescents according to gender and pubertal status.
Methods: Two hundred and eight obese children and adolescents (141 girls, 127 boys) aged between 5 and 18 years were included in the study. The children were divided into prepubertal and pubertal groups. A standard oral glucose tolerance test (OGTT) was carried out in all children. A total insulin level exceeding 300 mU/mL in the blood samples, collected during the test period, was taken as the insulin resistance criterion. Cut-off values for HOMA-IR were calculated by receiver operating characteristic (ROC) analysis.
Results: In the prepubertal period, the rate of insulin resistance was found to be 37% in boys and 27.8% in girls,while in the pubertal period, this rate was 61.7% in boys and 66.7% in girls. HOMA-IR cut-off values for insulin resistance in the prepubertal period were calculated to be 2.67 (sensitivity 88.2%, specificity 65.5%) in boys and 2.22 (sensitivity 100%, specificity 42.3%) in girls, and in the pubertal period, they were 5.22 (sensitivity 56%, specificity 93.3%) in boys and 3.82 (sensitivity 77.1%, specificity 71.4%) in girls.
Conclusions: Since gender, obesity and pubertal status are factors affecting insulin resistance, cut-off values which depend on gender and pubertal status, should be used in evaluation of insulin resistance.

Background: Local normative data for penile size will aid physicians in clinical practice. There are no studies on stretched penile length (SPL) in newborn Turkish boys.
Objective: To establish normative data for SPL of newborn Turkish boys and compare these with data from different countries. Methods: 514 newborn Turkish boys, who were not small for gestational age (SGA) or premature, were included in this cross-sectional study. SPLs of the newborns were measured by the same investigator. The correlations between SPL and gestational age, weight, length, and head circumference were evaluated.
Results: The 3rd percentile value for SPL was found as 3.00 cm in these Turkish newborns. Positive correlations were shown between SPL and height (r=0.240, p<0.001), weight (r=0.251, p<0.001), and head circumference (r=0.235, p<0.001). Multiple linear regression analysis showed that SPL positively correlated with height and head circumference (p=0.021 and p= 0.042, respectively).
Conclusions: his is the largest study on SPL in newborns from our country. This normative data can be used in clinical practice for defining micropenis.

Objective: To evaluate the nutritional status of Turkish high school adolescents using anthropometric indicators and to determine the relationship of nutritional status with gender and socioeconomic status (SES) in adolescents.
Methods: Six hundred eighty adolescent students (n=284 males, 396 females) aged 14-18 years were selected from 6 high schools of different regions. Nutritional status was evaluated according to the anthropometric indicators, which were based on the WHO criteria. Adolescents were grouped into three SES categories.
Results: The rates of being stunted, underweight, and overweight / obesity were 4.4%, 5.0% and 16.8%, respectively. Height and weight standard deviation scores (SDS) were significantly lower in adolescents with low SES (p<0.05). The frequency of stunting was significantly higher in adolescents with low SES (p=0.012). Frequency of underweight, overweight and obesity did not differ significantly between socioeconomic groups and genders (p>0.05).
Conclusion: Adolescents of low SES were shorter and thinner than those of other SES categories. Undernutrition needs to be addressed in low SES. Among all Turkish adolescents, the major nutritional problems were overweight and obesity. There were no SES and gender differences in prevalence of overweight and obesity among the Turkish school adolescents living in urban areas. Prevalence of obesity is rising, regardless of differences in SES and gender, in developing countries too.

Objective: In this study, we aimed to show the role of ghrelin in growth delay in children with constitutional delay of growth and puberty (CDGP).
Methods: Thirty male children with CDGP constituted the study group and fifteen healthy children with normal growth of similar ages-the control group. In both groups, fasting and postprandial plasma ghrelin levels, serum insulin-like growth factor-1 (IGF-1) and IGF-binding protein-3 (IGFBP-3) levels were determined.
Results: There were no differences in fasting and postprandial ghrelin levels (824.23±523.46 pg/mL and 447.26±259.92 pg/mL, respectively) in children with CDGP compared to the levels in the control group (687.38±481.43 pg/mL and 365.59±260.43 pg/mL, respectively; p>0.05). Differences in fasting and postprandial ghrelin levels were also similar in the two groups (394.44±369.10 pg/mL and 346.55±338.67 pg/mL, respectively; p>0.05). Serum IGF-1 levels were significantly depressed in children with CDGP compared to those in the control group (239.5±83.95 ng/mL and 339.20±63.08 ng/mL, respectively; p<0.05).
Conclusion: Decreased appetite and feeding problems in children with CDGP were not related to depressed ghrelin levels. In addition, ghrelin levels did not increase to compensate for the decreased appetite and feeding problems in CDGP.

Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive disease resulting from resistance to the action of adrenocorticotropic hormone (ACTH) on the adrenal cortex, which leads to isolated glucocorticoid deficiency with normal mineralocorticoid secretion. It may present in infancy or early childhood with hyperpigmentation, failure to thrive, recurrent infections, hypoglycemic attacks and convulsions that may result in coma or death. Laboratory investigations reveal low cortisol and androgen levels with high ACTH associated with normal renin-aldosterone axis. The disorder may be caused by mutations in the gene of ACTH receptor (MC2R), or mutations in the newly described melanocortin-2 receptor accessory protein (MRAP) namely, FGD type 1 and FGD type 2, respectively. Twenty five percent of FGD cases are due to the mutations of the ACTH receptor, while FGD type 2 accounts for approximately 15-20% of FGD cases. Here, we report a six-month-old male infant, who presented with recurrent hypoglycemic convulsions. Serum hormone analysis showed low cortisol and androgen levels associated with a high ACTH concentration. No mutation was found in the NR0B1 and MC2R genes excluding congenital adrenal hypoplasia and FGD type 1. We found a homozygous deletion (c. 106+1delG) in intron 3 of MRAP gene. To our knowledge, this is the first Turkish patient reported with FGD type 2 due to a known MRAP mutation.

Although hemangioendothelioma (HHE) is a commonly encountered hepatic tumor during infancy, HHE-related hypothyroidism is rare. We present a patient who developed HHE-related hypothyroidism during the neonatal period and showed marked improvement in hypothyroidism by regression of HHE. A 28-day-old boy with TSH level of 77 mIU/mL on neonatal screening and diagnosed as congenital hypothyroidism was started on L-thyroxine (L-T4) (11 µg/kg/day) therapy on the 21th day of life. On physical examination, the liver was palpable 5 cm below the right costal margin, and the thyroid gland was nonpalpable. Thyroid ultrasonography was normal. Although L-T4 dose was increased to 15 µg/kg/day, TSH was not suppressed and free T3 level remained low. HHE in both lobes of the liver was detected by abdominal ultrasonography and magnetic resonance imaging. Treatment was started with prednisolone 2 mg/kg/day and alpha-interferon 3 million U/m2/3 times per week. Thyroid dysfunction was thought to be due to type 3 iodothyronine deiodinase activity expressed by HHE. L-T4 therapy was changed to Bitiron® tablet, which includes both T4 and T3, and euthyroidism was attained within 1 month. Thyroid hormone requirement was reduced and treatment was discontinued after regression of the HHE. At the most recent visit, the patient was 21 months old and off treatment. His growth and neurological development were normal for age and he was euthyroid. HHE should be considered in cases with severe hypothyroidism resistant to high-dose thyroid hormone replacement. The treatment of HHE in combination with T4 and T3 therapy results in euthyroidism.

Neonatal diabetes mellitus (DM) develops within the first six weeks of life with basic findings including dehydration, hyperglycaemia, and mild or no ketonemia/ketonuria. It can be either transient or permanent. Here, we report a case of a one-month-old infant with permanent neonatal diabetes, due to pancreatic hypoplasia, accompanied by diabetic ketoacidosis (DKA). The hyperglycaemia and ketoacidosis resolved by the 14th hour of treatment, consisting of IV insulin and rehydration. Subsequently, insulin treatment was continued with neutral protamine hagedorn (NPH) insulin. Breastfeeding was started and was continued at intervals of three hours. Following initiation of breastfeeding, the stools became watery, loose, yellow-green in color, and frequent (8-10 times a day). They contained no blood or mucus. Replacement of pancreatic enzymes resulted in decreased stool frequency. Neonatal DM due to pancreatic hypoplasia and associated with DKA may mimic sepsis and should be kept in mind in all newborns who present with fever, dehydration, and weight loss.

Cleidocranial dysplasia (CCD) is a rare autosomal dominant skeletal disease. CCD is caused by mutation in the gene on 6p21 encoding transcription factor CBFA1, i.e. runt-related transcription factor 2(RUNX2). The disease is characterized by a persistently open anterior fontanelle and skull sutures, hypoplastic or aplastic clavicles, dental abnormalities, short stature, a wide pubic symphysis, and a variety of other skeletal changes. A major finding of CCD is hypoplasia or aplasia of clavicular bones resulting in the ability of the patient to approximate the shoulders. Delayed closure of the anterior fontanelle and of metopic sutures causes frontal bossing. We report a case of CCD in a 3.5-year-old boy who referred to our clinic because of an unclosed anterior fontanelle and emphasize the importance of clinical findings in CCD.