ESPE Abstracts

Introduction: The physiological process by which vitamin D regulates calcium and phosphorus metabolism, the major mineral constituents of bone tissue, is by far very well understood. However, the clinical implementation of vitamin D deficiency on bone fragility in childhood remains controversial.Objective: The aim of this case-control study is to investigate the prevalence of vitamin D deficiency among Lebanese children who experienced a ‘low-energy...

Introduction: Dyslipidemia has been recognized as a risk factor for cardiovascular diseases. Studies showed that the development of atherosclerotic lesions begins in childhood and progresses throughout life. While the prevalence of dyslipidemia in adults has been reported to be 10 times higher in Lebanon, there is no available data on the prevalence of dyslipidemic children in Lebanon.Objectives: This study was conducted to check if a protocol for univer...

Introduction: Hypoglycemia is a common problem in neonatal period associated with adverse neurological outcome and brain injury if treatment was not provided. AAP and PES recommended screening for hypoglycemia only in newborns with risk factors but many others neonates may present episodes of asymptomatic hypoglycemia without any known risk factor.Objectives: To assess the incidence of hypoglycemia in healthy full term neonates without any risk factors i...

Background: Acquisition and maintenance of fertility in mammals rely on the function of Gonadotropin Releasing Hormone (GnRH) neurons. During the juvenile period, GnRH neurons undergo morphological maturation, which involves changes in synaptic inputs and neuropeptide activation from afferent neurons. The functional importance of this maturation could be a pre-requisite for puberty onset. However, the mechanisms behind these dynamic changes have yet to be identified.<p cla...

Background: The nuclear receptor (NR) family comprises three main subfamilies: the steroid hormones receptors, the thyroid/retinoid hormone receptors and the orphan receptors. Proteins within the NR family share common domain architecture. These closely related receptors and their cognate ligand compounds play a key role in homeostasis, reproduction, growth and development. Despite their biological significance, their evolution and diversification remains to be elucidated....

Background: Heterozygous GNAS inactivating mutations cause pseudohypoparathyroidism type Ia (PHP-Ia) when maternally inherited and pseudopseudohypoparathyroidism (PPHP)/progressive osseous heteroplasia when paternally inherited. Mutations on the paternal, but not the maternal, GNAS allele are associated with intrauterine growth retardation (IUGR). Moreover, birth weights were lower with paternal GNAS mutations affecting exons 2–13 (including XL and Gαs) than with exo...

Background: GNAS gene is a complex imprinted locus, resulting in the expression of at least four transcripts (XL, NESP55, A/B and Gsα) characterized by their specific exon 1 and common exons 2-13. While Gαs is biallelically expressed in most tissues, XL is only expressed from the paternal allele. Maternally inherited, loss-of-function mutations affecting those GNAS exons that ...

Background: Androgen receptor (AR) gene mutations are the most frequent cause of 46,XY disorders of sex development and are associated with a variety of phenotypes, ranging from phenotypic women (complete androgen insensitivity syndrome) to milder degrees of undervirilization (partial and mild forms).Aims and objectives: To specify how a phenotype-genotype correlation can be refined by in vitro study based on the nature of amino acid substitutio...

Background: Primary generalized glucocorticoid resistance (PGGR) or Chrousos syndrome is a rare familial or sporadic condition caused by mutations in the hGR gene, which reduce tissue sensitivity to glucocorticoids. A new case of PGGR caused by a novel heterozygous point mutation in the hGR gene, which resulted in threonine (T) to isoleucine (I) substitution at amino acid position 556 in the ligand-binding domain of the receptor, was recently reported in a patient with an adre...

Background: Patients affected by pseudohypoparathyroidism type 1b (PHPI-b) develop resistance to PTH leading to hypocalcemia and hyperphosphoremia, which is often associated with resistance to TSH. PHP-Ib is associated with methylation changes at one or several differentially methylated regions (DMRs) within the GNAS complex locus, located at 20q13.2–13.3. This locus gives rise to several different transcripts (NESP55, XL, A/B), with varying patterns of imprinted expressi...