The Impact of Adiposity and Puberty on Thyroid Function in Children and Adolescents.

Background: In the context of a worldwide increase in childhood obesity, euthyroid hyperthyrotropinemia has been consistently reported and raises questions about its etiology, its potential metabolic complications, and its management. In this study we analyze the thyroid function with respect to BMI, pubertal status, and sex in children with obesity and discuss our results on an integrative context with the existent data from the literature. Methods: In this case-control study, we compared 389 children and adolescents with obesity to 158 controls. Age, sex, thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), BMI standard deviation score, and pubertal status were recorded. One factor-analysis of variance (ANOVA) was used with p < 0.05. Results: Mean serum TSH of children with obesity was higher (2.95 ± 1.2 mU/L) compared to normal weight group (2.42 ± 1.43 mU/L) (p < 0.0001). Only in females of both groups, serum TSH, T4, and T3 concentrations were all lower during puberty compared to prepuberty. In prepubertal girls and boys with obesity, a statistically significant correlation between TSH and BMI was found (r = 0.32, p = 0.012 and r = 0.47, p < 0.001, respectively), which is not sustained during puberty. Conclusions: Our results confirm the TSH elevation in children with obesity and indicates that puberty and adiposity have a differential sex-dependent impact on thyroid axis function.

Hyperthyrotropinemia in newly diagnosed cystic fibrosis patients with pancreatic insufficiency reversed by enzyme therapy.

Patients with cystic fibrosis (CF) commonly present with an elevated TSH concentration, suggesting subclinical hypothyroidism. Its relation to concomitant pancreatic insufficiency and its natural course upon initiation of enzyme replacement have not been adequately studied. Herein, we investigated the thyroid function in newly diagnosed infants with CF and monitored the course of thyroid function response to pancreatic enzyme substitution treatment. Fourteen, newly diagnosed infants with CF and pancreatic insufficiency, were followed every 6-8 weeks for 6 months ensuing onset of pancreatic enzyme substitution therapy. All infants had normal TSH values on neonatal screening. Ten out of 14 (71%) had hyperthyrotropinemia and normal freeT4 values at presentation. No patient received thyroxine. Upon follow-up, after 6 months, TSH values normalized in 90% of infants with CF and hyperthyrotropinemia. Serum selenium levels were negatively correlated with TSH levels. CONCLUSION: Mild TSH elevation is a frequent finding in newly diagnosed cystic fibrosis patients with pancreatic insufficiency during infancy. TSH elevation resolves in most cases after initiation of enzyme substitution and improvement of nutritional status without any substitutive therapy with thyroxine. What is Known: • Newly diagnosed infants with cystic fibrosis often present with a state of hyperthyrotropinemia suggesting subclinical hypothyroidism. What is New: • Pancreatic enzyme substitution and improvement of nutrition restores normal TSH levels without the need of thyroxine therapy.

A Case of Vitamin-D-Dependent Rickets Type 1A with Normal 1,25-Dihydroxyvitamin D Caused by Two Novel Mutations of the CYP27B1 Gene.

BACKGROUND: Vitamin-D-dependent rickets 1A (VDDR-1A) is caused by mutations of the renal CYP27B1 gene and is a rare form of rickets. Herein, we report a 20-month-old toddler who presented with inability to walk and failure to thrive. The clinical, biochemical and radiological findings were consistent with a diagnosis of rickets, specifically of the genetic type due to increased 25-OH vitamin D stores. METHODS AND RESULTS: Our patient was a compound heterozygote with 2 novel mutations: c.242G>A(p.Gly81Glu) and c.1144C>G (p.Pro382Ala) in the CYP27B1 gene. Analysis of both mutations with in silico models predicted a deleterious effect on 25-OH vitamin D 1α-hydroxylase function. Interestingly, the levels of 1,25-(OH)2 vitamin D were within normal limits. Our patient was initiated on 1α-hydroxyvitamin D (alfacalcidol) and supplemental calcium. Monitoring of bone metabolism showed a normalization of all bone metabolism serum indices after 3 months of therapy and, thereafter, only alfacalcidol was given at a maintenance dose. The clinical follow-up showed a dramatic improvement in musculoskeletal activity, and the patient regained acceleration in height and weight appropriate for his age. CONCLUSION: This rare case report of VDDR-1A with normal levels of 1,25-(OH)2 vitamin D enhances our awareness for this type of rickets in clinical practice.

Central precocious puberty in a boy with 22q13 deletion syndrome and NOTCH-1 gene duplication.

The 22q13 deletion syndrome or Phelan-McDermid syndrome is a neurodevelopmental disorder associated with developmental delay, hypotonia, delayed or absent speech, autistic-like behavior, normal to accelerated growth and dysmorphic faces. We report the occurrence of central precocious puberty in a boy diagnosed with Phelan-McDermid syndrome. At the age of 1 year, our patient presented with increased testicular volume for his age, bone age advancement and growth acceleration. Stimulated gonadotropin levels demonstrated a premature activation of the hypothalamic-pituitary-gonadal (HPG) axis. Central precocious puberty was treated with gonadotropin-releasing hormone (GnRH) analog. Molecular diagnosis with array-comparative genomic hybridization (CGH) revealed a major deletion of 5.8 Mb at the 22q13 chromosomal region and a 25 kb duplication at the 9q34.3 region that included the NOTCH-1 gene. On the background of 22q13 deletion syndrome and data from animals on the effect of abnormal NOTCH-1 gene expression on kisspeptin neuron formation, we discuss the probable role of Notch signaling in the premature activation of the HPG axis.

A novel mutation in the G4.5 (TAZ) gene in a Greek patient with Barth syndrome.

Barth Syndrome (BTHS) is a rare X-linked recessive inborn error of metabolism, which is characterized by dilated cardiomyopathy, neutropenia, skeletal myopathy and short stature. Barth Syndrome is associated with mutations in the tafazzin (TAZ) gene at Xq28 that result in cardiolipin deficiency and abnormal mitochondria. Here we report a 5.5-month old boy with BTHS phenotype who carries a novel missense T43P mutation in exon 2 of the TAZ gene.

Successful reconstitution of immunity in ADA-SCID by stem cell gene therapy following cessation of PEG-ADA and use of mild preconditioning.

Gene therapy is a promising treatment option for monogenic diseases, but success has been seen in only a handful of studies thus far. We now document successful reconstitution of immune function in a child with the adenosine deaminase (ADA)-deficient form of severe combined immunodeficiency (SCID) following hematopoietic stem cell (HSC) gene therapy. An ADA-SCID child who showed a poor response to PEG-ADA enzyme replacement was enrolled into the clinical study. Following cessation of enzyme replacement therapy, autologous CD34(+) HSCs were transduced with an ADA-expressing gammaretroviral vector. Gene-modified cells were reinfused following one dose of preconditioning chemotherapy. Two years after the procedure, immunological and biochemical correction has been maintained with progressive increase in lymphocyte numbers, reinitiation of thymopoiesis, and systemic detoxification of ADA metabolites. Sustained vector marking with detection of polyclonal vector integration sites in multiple cell lineages and detection of ADA activity in red blood cells suggests transduction of early hematopoietic progenitors. No serious side effects were seen either as a result of the conditioning procedure or due to retroviral insertion. Gene therapy is an effective treatment option for the treatment of ADA-SCID.