ESPE Abstracts

Introduction: Cardiovascular disease (CVD) is the major cause of morbidity and mortality in type 1 diabetes (T1D). Recent studies implicated deregulated phosphate homeostasis in the etiology of CVD. The objective of this study is to address the relationship between the phosphate-regulating hormone fibroblast growth factor 23 (FGF23) and cardiovascular risk factors in adults with and without type 1 diabetes (T1D).Methods:...

Management of DSD is a sensitive area within the field of paediatric endocrinology. On the one hand, major progress has been made in amongst others understanding the molecular genetic background and the germ cell cancer risk of certain DSD conditions. On the other hand, practices that were common in the past, such as early genital surgery have become strongly criticised and controversial nowadays, leaving clinicians as well as patients and their families with a lot of question...

Insulin-induced ovarian hyperstimulation and hyperandrogenization can cause virilization in children and adults. It rarely occurs in children and adolescents but when it does, it is usually caused by congenital adrenal hyperplasia or virilizing tumors. In very rare cases severe hyperandrogenism is caused by severe insulin resistance, either due to germline mutations in genes encoding the insulin receptor or proteins in downstream insulin signaling or due to insulin receptor an...

Introduction: Although many adolescents with gender dysphoria (GD) are being treated with GnRH analogues (GnRHa) and gender affirming hormones there is a paucity of data on the effects and side effects of this treatment in this population. We aimed to study short-term outcome of testosterone treatment in male adolescents with GD.Methods: Sixty-two adolescents who had been treated with GnRHa, and subsequently with testost...

In the past year, basic and genetic studies revealed again novel genes and mechanisms implicated in 46,XX and 46,XY DSD. The Fgf9-/- mouse model of human synostosis syndromes revealed an unexpected male-to-female sex reversal phenotype, so far not observed in humans. Specific heterozygous human WT1 gene variants located in the 4th zinc finger were found to cause 46,XX virilization due to (ovo-)testicular DSD, and the transcription factor...

Background: Individuals with androgen insensitivity syndrome (AIS) have an increased risk for developing a germ cell cancer (GCC). The risk is low during childhood; therefore, gonads are commonly preserved until after puberty. Little is known about GCC development in AIS during adulthood. This question is particularly relevant as many adult AIS women decline gonadectomy.Objective and hypotheses: To gain insight in attitudes towards gonadectomy in various...

Keywords: transgender, GnRH agonists, gender affirming hormones, final height, growth, pubertyBackground: Trans boys (TB) and trans girls (TG) who start medical gender-affirming treatment at Tanner stage 2-3 undergo early puberty suppression (ePS) with Gonadotropin-Releasing Hormone agonists (GnRHa) for several years and subsequently receive gender-affirming hormones (GAH), around 15-16 years. This treatment clearly inte...

Background: Loss of function variants in Steroidogenic Factor 1 (NR5A1/SF-1) lead to a broad spectrum of phenotypes, but data on the whole picture of phenotypes are currently lacking. We aimed to investigate the phenotype of individuals with SF-1 variants in a large international cohort.Methods: We identified the individuals through the international I-DSD network and through contacting researchers from previous publicat...

Background: Loss-of-function variants in the NR5A1 gene are frequent causes of 46,XY differences of sex development (DSD). To date, the Human Gene Mutation Database contains 291 NR5A1 variants, most of which are missense (69%). Mouse models demonstrated the effect of loss of SF-1 on sex development, but the interactome of SF-1 is huge and an explanation for the broad phenotype is still missing. Controversies exist as: a) in vitro transactivation assays of NR5A...

Introduction: Boys born small for gestational age (SGA) often have undermasculinized genitalia. Little is known about the pubertal development and gonadal function on a longer-term in this specific group of males.Aims: To determine the (pubertal) development and long-term urological and endocrine outcome of undermasculinized boys born SGA compared to undervirilized boys born appropriate for gestational age (AGA).<p c...