A phenocopy of CAII deficiency: a novel genetic explanation for inherited infantile osteopetrosis with distal renal tubular acidosis

The rare bone thickening disease osteopetrosis occurs in various forms, one of which is accompanied by renal tubular acidosis (RTA), and is known as Guibaud-Vainsel syndrome or marble brain disease. Clinical manifestations of this autosomal recessive syndrome comprise increased bone density, growth failure, intracerebral calcification, facial dysmorphism, mental retardation, and conductive hearing impairment. The most common cause is carbonic anhydrase II (CAII) deficiency. Several different loss of function mutations in CA2, the gene encoding CAII, have been described. To date, there have been no exceptions to the finding of CAII deficiency in patients with coexistent osteopetrosis and RTA. Most often, the RTA is of mixed proximal and distal type, but kindreds are reported in which either distal or proximal RTA predominates. We report the molecular genetic investigation of two consanguineous kindreds where osteopetrosis and distal RTA (dRTA) were both manifest. One kindred harbours a novel homozygous frameshift alteration in CA2. In the other, CAII levels were normal despite a similar clinical picture, and we excluded defects in CA2. In this kindred, two separate recessive disorders are penetrant, each affecting a different, tissue specific subunit of the vacuolar proton pump (H(+)-ATPase), providing a highly unusual, novel genetic explanation for the coexistence of osteopetrosis and dRTA. The osteopetrosis is the result of a homozygous deletion in TCIRG1, which encodes an osteoclast specific isoform of subunit a of the H(+)-ATPase, while the dRTA is associated with a homozygous mutation in ATP6V1B1, encoding the kidney specific B1 subunit of H(+)-ATPase. This kindred is exceptional firstly because the coinheritance of two rare recessive disorders has created a phenocopy of CAII deficiency, and secondly because these disorders affect two different subunits of the H(+)-ATPase that have opposite effects on bone density, but which have only recently been determined to possess tissue specific isoforms.

The relationship between serum adiponectin, tumor necrosis factor-alpha, leptin levels and insulin sensitivity in childhood and adolescent obesity: adiponectin is a marker of metabolic syndrome

OBJECTIVE

This study aimed (a) to investigate the relationship between the degree of obesity and serum adiponectin, tumor necrosis factor (TNF)-α, leptin, insulin levels and the lipid profile; (b) to clarify the relationship between insulin resistance/glucose tolerance and adipocytokine levels; and (c) to investigate the value of adipocytokine levels as a marker of metabolic syndrome (MS).

METHODS

We studied 151 obese children and adolescents (86 boys and 65 girls; mean age was 12.3±2.4 years). We defined obesity as a body-mass index (BMI) z-score more than 2 SD above the mean for age and sex. The control group consisted of 100 children (48 boys, 52 girls, mean age 12.4±2.5 years). Fasting glucose, insulin levels and lipid profiles were measured in all cases and controls after a 12-hour fast. Adiponectin, TNF-α, and leptin levels were measured in the subjects who participated in the adipocytokine branch of the study. An oral glucose tolerance test (OGTT) was also performed in all obese patients. Obese patients were grouped into three subgroups according to their glucose tolerance and insulin sensitivity assessment, and also according to whether they were grouped as MS or not.

RESULTS

Serum levels of total cholesterol, LDL and VLDL cholesterol, log triglyceride, insulin, leptin and TNF-α were higher, whereas HDL and square root adiponectin levels were lower in the obese group when compared with controls. Multiple regression analysis among BMI-z score, LDL, triglyceride, HOMA-IR, leptin and TNF-α as determinants of adiponectin revealed that BMI-z score was the only determinant for adiponectin (r:-0.45, p<0.0001). Adiponectin levels in hyperinsulinemic and impaired glucose tolerance groups (IGT) tended to be lower than in normoinsulinemic obese children, however, the difference was not significant. There was a weak negative correlation between adiponectin levels and increasing severity of insulin resistance (r=-0.23, p=0.005) in the groups of obese subjects. Mean serum adiponectin level in subjects with MS was lower than in subjects without MS (p=0.008).

CONCLUSIONS

Evaluation of serum adiponectin levels might contribute to an early intervention in obese children with MS.

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

Hashimoto's 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.

Congenital adrenal hyperplasia in Turkey: a review of 273 patients

In this study the clinical and epidemiological characteristics of congenital adrenal hyperplasia were evaluated retrospectively from the records of 273 patients managed in our clinic over a 25-year period. 21-Hydroxylase deficiency was present in 234 patients (85.7%), simple virilizing form in 134 (110 F, 24 M), salt-losing form in 85 (71 F, 14 M) and late on-set form in 15 girls. 11 beta-Hydroxylase deficiency was diagnosed relatively frequently (13.5%) among our patients with congenital adrenal hyperplasia; one girl had 17 alpha-hydroxylase deficiency and one boy had 3 beta-hydroxy steroid dehydrogenase deficiency. The median chronological age of diagnosis was 12 months (1 day-16.6 years) in patients with classical congenital adrenal hyperplasia. Chromosomal sex was 46, XX in a total of 221 patients and 46, XY in 52. Ninety-one girls were considered to be male before diagnosis was established and male sex was assigned in 31 of them due to development of male gender identity at diagnosis. Parental consanguinity rate among families of patients was higher than the general population in Turkey (56.4% vs 21%). Our overall figures show that the incidence of congenital adrenal hyperplasia is expected to be high due to a high rate of consanguinity in our populations and the patients remain frequently undiagnosed during the neonatal period. Therefore screening may be beneficial in our population.

GnRH stimulation test in precocious puberty: single sample is adequate for diagnosis and dose adjustment

OBJECTIVE

Gonadotropin stimulation test is the gold standard to document precocious puberty. However, the test is costly, time-consuming and uncomfortable. The aim of this study was to simplify the intravenous gonadotropin-releasing hormone (GnRH) stimulation test in the diagnosis of precocious puberty and in the assessment of pubertal suppression.

METHODS

Data pertaining to 584 GnRH stimulation tests (314 tests for diagnosis and 270 for assessment of pubertal suppression) were analyzed.

RESULTS

Forty-minute post-injection samples had the greatest frequency of "peaking luteinizing hormone (LH)" (p<0.001) in the diagnostic tests when the cut-off value was taken as 5 IU/L for LH, 40th minute sample was found to have 98% sensitivity and 100% specificity in the diagnosis of precocious puberty, while the sensitivity and specificity of the 20th minute sample was 100% in the assessment of pubertal suppression.

CONCLUSION

LH level at the 40th minute post-injection in the diagnosis of central precocious puberty and at the 20th minute post-injection in the assessment of pubertal suppression is highly sensitive and specific. A single sample at these time points can be used in the diagnosis of early puberty and in the assessment of pubertal suppression.

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.

Fludrocortisone treatment in a child with severe cerebral salt wasting

Hyponatremia is a common complication of intracranial disease or surgery. An evaluation should be undertaken to determine whether cerebral salt wasting (CSW) or inappropriate secretion of antidiuretic hormone is present as a cause. Since the treatment principles are completely different in the two pathological states, differential diagnosis is very important. CSW is defined as the renal loss of sodium leading to hyponatremia and decreased extracellular fluid volume. In the literature, it has been noted that mineralocorticoid administration can be useful in CSW cases. We herein present an 11-year-old boy who developed hyponatremic seizures after intracranial tumor resection. He was diagnosed with CSW on the basis of high urinary sodium excretion and increased urine output, together with signs and symptoms of dehydration. Despite intensive fluid and salt therapy, we were unable to decrease the urinary output. Therefore, fludrocortisone therapy was administered and his urinary output and sodium excretion were decreased and his serum sodium level was normalized. In conclusion, in addition to fluid and salt replacement, mineralocorticoid supplementation also seems to be a safe and effective treatment for CSW.

True hermaphroditism: clinical features, genetic variants and gonadal histology

True hermaphroditism is a rare cause of intersexuality in which both ovarian and testicular tissue is present in the same individual. We present the clinical findings, karyotype, gonadal histology and management of eight patients with true hermaphroditism. Their ages ranged from 43 days to 12 years at the first evaluation. The presenting symptoms were ambiguous genitalia (6 patients), isolated clitoromegaly (1 patient) and hypospadias (1 patient). The most common karyotype was 46,XX (6 patients). In one patient the karyotype was 46,XY and in another 45,XO/46,XY mosaicism, which is rare in the literature. A vagina was found by genitography in all patients, and at laparotomy the uterus was found normal in five patients, hypoplastic in one patient, as a fibrous band in one, and absent in the remaining patient. Histological investigation of the gonads revealed bilateral ovotestis in two patients, ovotestis plus ovary in two patients, and ovary on one side and testis on the other side in three patients. Five patients were assigned to the female sex, and three to the male sex. One of these patients was changed from male to female after evaluation.

Inappropriate use of potent topical glucocorticoids in infants

Topical therapy with glucocorticoids (GCs) is used commonly in chronic dermatoses. Side effects are less common compared to systemic use; however, newer potent preparations may have serious side effects. A potential danger is their inappropriate use. Three infants who developed iatrogenic Cushing's syndrome and prolonged adrenal suppression in the course of GC therapy for simple diaper dermatitis are described. One patient also developed steatohepatitis which is uncommon with local GCs.

Assessment of thyroid function during the long course of Hashimoto's thyroiditis in children and adolescents

CONTEXT

The prognosis of Hashimoto's thyroiditis (HT) in children and adolescents is not well known and studies reporting long-term outcome of the disease are scarce.

OBJECTIVE

To assess the thyroid hormone status during long-term follow-up and to establish the prognosis of children and adolescents with HT.

PATIENTS

One hundred and twenty-nine patients with HT were re-evaluated for thyroid hormone status after a mean follow-up period of 50 months.

RESULTS

Seventy-seven per cent of the euthyroid patients were still euthyroid, while 21.1% of these patients became hypothyroid at the time of re-evaluation. However, 69.5% of hypothyroid patients remained hypothyroid (overt or subclinical) and 30.5% recovered.

CONCLUSION

HT is a dynamic process. Thyroid functions can show variation during follow-up. Therefore, thyroid function tests should be repeated periodically to detect progression to hypothyroidism in initially euthyroid patients as well as reversibility of hypothyroidism.

A novel mutation in leukocyte adhesion deficiency type II/CDGIIc

Leukocyte adhesion deficiencies (LAD) are autosomal recessive immunodeficiency syndromes characterized by severe and recurrent bacterial infections, impaired wound healing and leukocytosis. Block in different steps in the leukocyte adhesion cascade causes different types of leukocyte adhesion deficiencies, LAD type I, II and III. In LAD type II, the rolling phase of the leukocyte adhesion cascade is affected due to mutations in the specific fucose transporter GFTP (GDP fucose transporter), causing defect in the biosynthesis of selectin ligands on leukocytes. Thus this syndrome is also called congenital disorder of glycosylation IIc (CGDIIc). LAD II/CGDIIc is very rare and has been diagnosed in nine children to date. Fever, leukocytosis, typical dysmorphic features, growth, psychomotor retardation and the Bombay blood group, are characteristic findings in patients. Here, we describe two Turkish siblings with a novel mutation in GFTP. They both have the characteristic features of the syndrome. The older sibling died of severe bacterial pneumonia at the age of 3 years. The younger sibling, diagnosed at the age of 3 months, responded to high dose oral fucose supplementation. Secundum atrial septal defect which was not described in previously reported patients, but present in both of our patients, may primarily related to the defect in fucosylation.

Screening for congenital hypothyroidism in Turkey

A pilot study was performed to determine the incidence of congenital hypothyroidism (CH) in Turkey and to build a model for nationwide screening. From December 1991 to December 1992, 30,097 newborns were screened for CH using a primary measurement of thyroid stimulating hormone in capillary blood on days 3-5 of life. Samples were obtained in collaboration with the ongoing nationwide phenylketonuria screening programme. Eleven cases of primary CH were detected giving the incidence of 1:2736. Recall rate was 2.3%. Replacement therapy with L-thyroxine was started after the confirmation of diagnosis. The median age at the initiation of replacement therapy was 23 days (range 7-35 days).

CONCLUSION

The incidence of CH is notably higher in Turkey than reported in most other countries. Iodine deficiency and/or dyshormonogenesis might contribute to this high incidence. This result emphasizes the necessity of a nationwide screening programme.

Thyroid involvement in Langerhans cell histiocytosis: a report of two cases and review of the literature

Langerhans cell histiocytosis (LCH) is a disorder with unclear etiology and pathogenesis characterized by abnormal clonal proliferation and accumulation of antigen presenting Langerhans' cells at various tissues and organs. Almost all organs or systems may be involved, and the prognosis depends on the involved sites and the presence of organ dysfunction. Thyroid tissue is a rarely affected site in children, and without histopathological evaluation it may be difficult to distinguish from other thyroid disorders because of the similar physical examination, laboratory and imaging findings. Here we report on two patients with histopathologically proven thyroid involvement of LCH. Additionally, the differential diagnosis of diffusely enlarged or multinodular thyroid glands in children is discussed, and a review of the literature of thyroid involvement in LCH is given. In the differential diagnosis of enlarged thyroid glands, especially in the presence of other endocrinological manifestations, LCH must be taken into consideration.

Comparison of stimulated growth hormone levels in primed versus unprimed provocative tests. Effect of various testosterone doses on growth hormone levels

OBJECTIVE

To show the importance of priming prior to growth hormone (GH) stimulation tests in the diagnosis of GH deficiency, the effect of different doses and schedules of testosterone (T) on GH levels.

PATIENTS AND METHODS

Eighty-four prepubertal and early pubertal boys whose heights were 2 SD below the mean and height velocities <4 cm per year and who failed in GH stimulation tests were included in the study. The boys were divided into two groups: the first group consisting of 41 boys was primed with 62.5 mg/m(2) (low dose testosterone - LDT) and the second group consisting of 43 boys with 125 mg/m(2) depot testosterone (conventional dose testosterone - CDT) intramuscularly 1 week before the stimulation test. Twenty-one boys out of 36 who failed in GH stimulation tests after one dose T injection were treated with three doses of 62.5 mg/m(2) T (multiple dose testosterone - MDT) injections monthly and retested.

RESULTS

The GH levels increased from 4.80 +/- 2.78 to 11.50 +/- 8.84 ng/ml and from 4.76 +/- 2.46 to 12.98 +/- 8.30 ng/ml by priming with LDT and CDT respectively. The increment of mean GH levels by both LDT and CDT were found to be similar (p = 0.443). The peak GH levels were found to be elevated >10 ng/ml in 22/41 (54%) and 26/43 (60%) who received LDT and CDT respectively (p = 0.528). The mean GH level of 21 boys who received MDT was increased from 5.38 +/- 2.50 ng/ml (by priming with one dose T) to 10.19 +/- 6.13 ng/ml (p = 0.004). Twelve (57%) of 21 boys who received MDT responded to GH stimulation test >10 ng/ml. The T level increased from 0.71 +/- 0.97 to 4.54 +/- 2.80 ng/ml by LDT (p < 0.001) and from 0.65 +/- 0.71 to 7.18 +/- 3.18 ng/ml by CDT (p < 0.001). The increment of T level was higher by CDT than LDT (p = 0.001). There was no correlation between T and peak GH levels after priming.

CONCLUSION

LDT is as effective as CDT in priming of GH stimulation tests. The ones who failed in GH stimulation tests after one dose T injection can be primed with MDT. The stimulated GH level after priming was related neither to the plasma level of T nor the dose of T.

Hyperthyroidism After Allogeneic Hematopoietic Stem Cell Transplantation: A Report of Four Cases

Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for many hematological disorders, primary immunodeficiencies, and metabolic disorders. Thyroid dysfunction is one of the frequently seen complications of HSCT. However, hyperthyroidism due to Graves' disease, autoimmune thyroiditis, and thyrotoxicosis are rare. Herein, we report a series of 4 patients who were euthyroid before HSCT but developed hyperthyroidism (3 of them developed autoimmune thyroid disease) after transplantation.

Review of Turkish patients with growth hormone insensitivity (Laron type)

Clinical spectrum and endocrine details of thirteen Turkish children (age 0.3-14.2 years; eight females and five males; ten prepubertal, three pubertal) with growth hormone insensitivity are presented. All patients display phenotypical features of severe growth hormone deficiency. The diagnosis based on height standard deviation score (SDS), basal growth hormone (GH), basal insulin-like growth factor I (IGF-I, IGF-I response in an IGF generation test and growth hormone binding protein (GHBP) measurements. The median height SDS was -7.4 (range -3.2 to -10), weight for height index was 100 (range 81-152) and bone age/height age ratio was 2 (range 1.6-3.3). Endocrine investigations showed a median basal GH concentration of 61.4 mU/l (range 23.5-120 mU/l). Basal IGF-I level was below 10 ng/ml in all patients except one. None of the patients showed a significant IGF-I response to injections of GH (0.1 U/kg body weight for 4 days). The median IGFBP-3 level was 0.23 mg/l (range 0.1-0.56 mg/l). The GHBP level was undetectable in all of 10 patients. The high number of patients in our center may be due to the high rate of consanguinity among the Turkish population and the referral facility of our center in the area. These patients may benefit from the new therapy with recombinant human IGF-I.

Age-related differences in serum insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 levels in congenital hypothyroidism

It is well established that thyroid hormones play a fundamental role in normal growth and development. The complex relationship between thyroid hormone and the growth hormone-insulin-like growth factor axis is not completely understood. We investigated age-related differences in serum insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) levels in 43 patients with primary congenital hypothyroidism. These patients were classified into five age groups (Group I: 0-1 month, Group II: 1 month-1 year, Group III: 1-5 years, Group IV: 5-9 years, Group V: 9-13 years). Patients diagnosed in the first month of life did not display a significant difference in serum IGF-I and IGFBP-3 levels compared to age-matched controls (p > 0.05). However, in groups II to V, IGF-I and IGFBP-3 levels were significantly lower than in controls (p < 0.05). Thyroid hormone replacement therapy increased serum IGF-I and IGFBP-3 levels significantly in 26 hypothyroid children (p < 0.05). Although serum IGF-I and IGFBP-3 levels increase in an age dependent manner in normal children, this increment was not observed in hypothyroid children.

Marker assisted genetic analysis of non-brittle rachis trait in barley

Brittle rachis is a head shattering mechanism of barley. Two tightly linked complementary genes, btr1 and btr2, were believed to control the non-brittle rachis trait. Position of non-brittle rachis loci btr1btr2 on the short arm of Chromosome 3 was investigated using RFLP markers. Two approaches were employed. First, a Hordeum vulgare subsp. spontaneum fragment that confers brittleness in a cv. Bowman near isogenic line was detected. This fragment is 18-33 cM in length and contains MWG798B, ABG057, MWG014, BCD706 and KFP216 markers of the short arm of Chromosome 3. In the second approach, position of btr1 locus in a H. vulgare subsp. spontaneum (Wadi Qilt 23-38)xH. vulgare subsp. vulgare (cv. Harrington) cross was detected using a selective genotyping approach in BC2F1 generation. F-tests and analysis of genotypic compositions of BC2F1 lines showed that btr1 locus, and supposedly the tightly linked btr2 locus, is in 4.3 cM KFP216-RisP114 interval of short arm of Chromosome 3. Results also yielded clues for the presence of at least two additional loci that affect the non-brittle rachis trait. Allelism tests using genotypes with known non-brittle rachis gene compositions provided additional evidence for presence of such loci.

mtDNA nt3243 mutation, external ophthalmoplegia, and hypogonadism in an adolescent girl

A 14-year-old girl presented with a 3-month history of easy fatigue and exercise intolerance, especially when climbing stairs. She had a mild ptosis and mild limitation of upward gaze. Her puberty was delayed, and she manifested hypogonadotrophic hypogonadism. Serum lactic and pyruvic acids were elevated. Cranial magnetic resonance imaging was normal. Muscle biopsy documented typical ragged-red fibers. A point mutation at nucleotide 3243 in the tRNALeu(UUR) (typical mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) mutation) was detected in mitochondrial DNA from both blood and muscle tissues, indicating that our patient was suffering from a mitochondrial myopathy. Hypogonadism may be a manifestation of the MELAS nucleotide 3243 mutation.

Magnetic resonance imaging in growth hormone deficiency: relationship between endocrine function and morphological findings

Magnetic resonance imaging (MRI) using gadopentetate dimeglumine (Gd-DTPA) improves the delineation of hypothalamic-pituitary structures and facilitates the detection of anatomical abnormalities which are indicators of permanent growth hormone deficiency (GHD). The aim of this study was to determine the frequency of neuroradiological abnormalities in 85 (52 M, 33 F) patients with hereditary or idiopathic forms of isolated GHD (IGHD) or multiple pituitary hormone deficiency (MPHD) and also to investigate the relationship between anatomical findings and hormonal status. Pituitary hypoplasia with absent or thin infundibulum and ectopic posterior pituitary (EPP) were the most frequent findings in 39 patients with MPHD, whereas in 46 patients with IGHD the most frequent finding was pituitary hypoplasia without neuroradiological abnormalities. All patients whose infundibulum was not visualized after Gd-DTPA injection belonged to the MPHD group; therefore, absence of pituitary stalk can be a good indicator of the severity of hormonal deficiencies. Pituitary hypoplasia was found in all patients with familial IGHD. Among patients with abnormalities of the hypothalamic pituitary area on MRI, normal or breech delivery frequency distributed equally. Therefore it seems that mechanical or hypoxic prenatal events cannot be the primary etiological factor in all patients with neuroradiological abnormalities since half of these patients had normal delivery and birth history. The localization of the bright spot of the posterior pituitary at the level of the median eminence, midstalk position or at the end of the infundibulum may suggest a neuronal migration defect which may occur during early embryogenesis. In conclusion, in children with GHD a careful examination of the hypothalamic pituitary area by MRI after enhancement helps to establish the diagnosis and predicts the prognosis.

Urinary bisphenol A levels in prepubertal children with exogenous obesity according to presence of metabolic syndrome

OBJECTIVES

Recent studies have shown a potential link between chronic exposure to Bisphenol A (BPA) and exogenous obesity, the prevalence of which has been increasing dramatically in all age groups and particularly among children in the last decades. In this study, we aimed at comparing BPA exposure levels between controls and otherwise healthy, drug-naive, pre-pubertal children having exogenous obesity with/without metabolic syndrome.

METHODS

A total of 63 pre-pubertal children with exogenous obesity whom 27 of them having metabolic syndrome attending Hacettepe University Ihsan Dogramaci Children's Hospital were included in this study. The control group consisted of 34 age- and sex-matched healthy children with no significant underlying medical conditions. Urinary BPA levels were measured using LC-MS/MS (high-performance liquid chromatography coupled with tandem mass spectrometry) methodology.

RESULTS

Urinary BPA levels among obese children were significantly higher than those of the control group (median: 22.9 μg/g-creatinine and 6.9 μg/g-creatinine, respectively; p=0.0001). When adjusted with generalized linear models for age, gender and z scores of body mass index, obese children having metabolic syndrome had significantly higher urinary BPA levels than obese children without metabolic syndrome and both obese groups had considerably elevated levels of urinary BPA than the controls (estimated marginal mean ± standard error: 42.3 ± 7.4 μg/g-creatinine, 22.6 ± 3.5 μg/g-creatinine and 12.1 ± 2.5 μg/g-creatinine, respectively, p=0.0001).

CONCLUSIONS

This study shows much higher BPA exposure among obese children with metabolic syndrome during the prepubertal period.

Anemia and neutropenic fever with high dose diazoxide treatment in a case with hyperinsulinism due to Munchausen by proxy

BACKGROUND

The etiology of hyperinsulinemic hypoglycemia in adolescents is similar to that of adults. Patients resistant to medical treatment may undergo pancreatectomy. Diazoxide is the mainstay of medical treatment. Rarely bone marrow suppression is reported due to diazoxide.

PATIENT

An adolescent with severe hyperinsulinemic hypoglycemia was referred for pancreatectomy after she was treated with high doses of diazoxide, octreotide and glucose. She developed anemia and febrile neutropenia in the course of diazoxide treatment that resolved with cessation of medication. The cause of the hyperinsulinemia proved to be classical Munchausen by proxy.

CONCLUSION

This is the first report of bone marrow suppression involving erythroid series by diazoxide. Follow-up of blood count may be considered in patients on high dosages since anemia may be dose dependent. Munchausen by proxy poses a serious threat to children with significant morbidity and mortality. Awareness and a high index of suspicion in clinical settings with unusual causes are the mainstay for the diagnosis.

Nine novel growth hormone receptor gene mutations in patients with Laron syndrome

The GH receptor (GHR) is a member of the cytokine receptor superfamily; GH binding protein is the solubilized extracellular domain of the GHR. Abnormalities in the GHR produce an autosomal recessive form of GH resistance, the Laron syndrome, characterized by growth failure and the clinical appearance of severe GH deficiency despite elevated circulating GH levels. In 13 unrelated patients with undetectable levels of GH binding protein, we characterized nine novel mutations in the GHR gene. These molecular defects comprise three nonsense mutations (Q65X, W80X, and W157X), one frameshift (36delC), two splice defects (G-->A at 70 + 1, C-->T at 723), and three missense mutations (C38S, S40L, and W50R) located in the extracellular domain of the receptor, and thus would be expected to interfere with GH binding activity. These results further confirm the broad heterogeneity of mutations underlying this rare GH resistance syndrome.