ESPE Abstracts

Mutations in the GH1 gene cause isolated growth hormone deficiency (IGHD) by affecting production, secretion, and stability of growth hormone as well as its binding to GHR. A smaller isoform of GH1 is inactive and is linked to IGHD. While studying the impact of small GH isoform, we noticed that cells with the short 17.5 kD version of GH looked different from the control cells. We found that the production of short GH isoform distorts the cell morphology, contributing to detrim...

Background: Disorders of sex development (DSD) characterize incomplete or disorganized genital or gonadal development. One in 4500 births requires genetic and endocrine studies due to abnormal external genitalia or gonadal dysgenesis and only 50% of the cases receive a definitive diagnosis. There are several genes that participate in both sex determination and differentiation processes. Mutations in NR5A1 gene, which encoding SF1, a transcription factor, are responsib...

Background: A portion of 160 kb on Xp21.2 is defined as dosage sensitive sex reversal, including NR0B1, which is considered the most likely candidate gene involved in XY gonadal dysgenesis if overexpressed. The excess of NR0B1 gene product seems to disturb testicular development by down regulating NR5A1, WT1, and SOX9. Xp duplication causes insufficient SRY expression leading to testis development failure. However, NR0B1 si...

Background: Thyroid hormone plays a key role in bone mineral homeostasis and significant alterations in its circulating levels have been associated with an impairment in skeletal growth during childhood. To date, the effects of subclinical hypothyroidism (SH) on bones have not been studied and the management of this condition is still debated.Aim: To evaluate bone mineral density (BMD) in children with mild, persistent S...

Cytochrome P450 oxidoreductase (POR) is the obligatory redox partner of steroid and drug-metabolizing cytochrome P450s located in the endoplasmic reticulum. Mutations in POR cause a broad range of disorders like congenital adrenal hyperplasia that may resemble bone malformations resembling Antley-Bixler syndrome. Genome sequencing studies have revealed the existence of a POR missense variant P228. We aimed to determine the detailed functional impact of POR variant P228L for it...

Background: A broad spectrum of human diseases, including abnormalities in steroidogenesis, are caused by mutations in the NADPH cytochrome P450 oxidoreductase (POR) (1-2). Cytochrome P450 proteins perform several reactions, including metabolism of steroids, drugs and other xenobiotics. Therefore, genetic variations in POR can impact many different metabolic pathways by changing the activities of cytochromes P450 (1). In 2004 the first human patients with defe...

Liquid chromatography associated with tandem mass spectrometry (LC-MS/MS) is currently considered the gold standard for steroid measurement. The aim of this study was to compare traditional immunoassay and LC-MS/MS methods for androgens measurement before and after human recombinant chorionic gonadotrophin (hrCG) stimulation in children with diagnosis of disorder of sex development (DSD) with 46,XY karyotype and past of normal testosterone secretion. We evaluated 19 patients, ...

Background: Steroidogenic factor-1 (SF-1), denominated as nuclear receptor subfamily five group A member 1 (NR5A1), is an orphan receptor that regulates several steps of adrenal and gonadal development. Mutations in its gene are responsible for different phenotypes of disorders of sex development (DSD).Objective and hypotheses: To study the functional impact of two novel NR5A1 mutations, the p.C247* and p.K396Rfs*34, both identified within the l...

Background: Differential diagnosis between XY partial (PGD) and mixed gonadal dysgenesis (MGD) was initially established by histological evaluation; however, when there is a 45,X lineage there are differences not only in clinical aspects but also in prognosis.Objective and hypotheses: The aim of this work was to analyze clinical picture of patients with genital ambiguity due to testicular dysgenesis, with and without a 45,X lineage, and compare these con...

Background: Recent data describe that the gonads of patients with partial gonadal dysgenesis (PGD) and mutation in the NR5A1 gene can present with a different histological pattern.Objective and hypotheses: To evaluate histological aspects of PGD caused by NR5A1 mutations.Method: Five patients with PGD, a history of gonadal biopsy or gonadectomy and confirmed mutation on NR5A1 gene were selected from a Bra...