ESPE Abstracts

Duplications of the dosage sensitive sex locus Xp21.2 have been associated with 46,XY gonadal dysgenesis (GD) for nearly 25 years. In the past, duplications have always included the NR0B1 (nuclear receptor subfamily 0 group B, member 1, also known as DAX1) gene, a known antagonist of SF1 (Steroidogenic Factor 1) dependent SOX9 (SRY Box 9) activation and the GD was attributed to its "double gene dose". However, recent findings have questioned the neces...

Background: Steroidogenic factor 1 (encoded by the NR5A1 gene) is a transcriptional regulator of genes involved in gonadal development and steroidogenesis. Mutations in NR5A1 are associated with a wide phenotypic spectrum in 46,XY individuals ranging from partial/complete gonadal dysgenesis or anorchia, ambiguous genitalia, hypospadias, to infertility. However, little is known about the longitudinal course of endocrine markers for Sertoli and Leydig cell func...

Background: Steroidogenic factor (SF1, NR5A2) regulates multiple genes known to be involved in gonadal development, adrenal development, steroidogenesis, and gonadotroph development. Heterozygous mutations in the NR5A1 gene have been described in association with mild to severe gonadal dysgenesis with or without adrenal failure. Homozygous mutations are rare and have also been described in association with gonadal dysgenesis with or without adrenal failure.<p class="abstex...

Background: Disorders (or differences) of sex development (DSD) are rare congenital conditions in which the development of chromosomal, gonadal, or anatomical sex is atypical. The luteinizing hormone/chorionic gonadotropin receptor (LHCGR) is important for male sex development. LHCGR mutations can cause Leydig cell hypoplasia, which is an autosomal recessive disorder.Objective and hypotheses: We found two heterozygous mutations in the LHCGR, a n...

Background: 17-β-hydroxysteroid dehydrogenase 3 (17-β-HSD3) deficiency is a rare disorder of sex development due to impaired conversion of androstenedione to testosterone. Children with 46,XY karyotype often have female appearing external or ambiguous genitalia at birth. At the time of puberty, virilisation can occur. Therefore 46,XY patients with HSD17B3 gene defects should be raised as male.Objective and hypotheses: When a child with 46,XY ka...

Introduction and objective: Gonadectomy was carried out for a long time after the diagnosis of complete androgen insensitivity syndrome (CAIS). It is now recommended to leave the gonads in situ in order to guarantee endogenous hormone production. It is unclear how best to clinically monitor testicular function. The aim of the study was to investigate whether inhibin B can be used as a future follow-up parameter to screen for gonadal function in CAIS p...

Introduction: Androgens are essential for the development of male sex characteristics. Testosterone (T) production from androstenedione (A) by the Hydroxysteroid 17-Beta Dehydrogenase 3 (HSD17B3) in gonadal Leydig cells triggers the differentiation of the Wolffian ducts into epididymis, vas deferens, seminal vesicles and the prostate. Shortly after, the virilisation of the external male genitalia starts through the conversion of T into dihydrotestosterone (DHT...

Background: The most common endocrine cause of growth disorders in childhood is growth hormone deficiency (GHD). The rare monogenic forms of GHD are inherited as autosomal dominant or recessive traits and manifest as isolated deficiency or in combination with other hormone deficiencies. Here, we report on a three-year-old girl with a severe growth retardation (height 77 cm, – 5.6 S.D.S.). She is the only child of non-consanguineous parents from northern Ira...

Background: Individuals born with a 45,X/46,XY karyotype can present with diverging phenotypes from normal male, Turner-like to ambiguous genitalia, the latter classically being called mixed gonadal dysgenesis. No correlation between phenotype and degree of mosaicisms in the karyotype could be ascertained so far, making clinical management of these patients difficult.Objective: To understand, if androgen action through the androgen receptor (AR) is compr...

Introduction: Burosumab was approved for treatment of pediatric patients with X-linked hypophosphatemia (XLH). However, data on its efficacy in adolescents (age > 12 years) and in real-world settings are lacking.Material and methods: Here we assess the effects of 12 months burosumab treatment on mineral homeostasis in 77 pediatric XLH patients (50 children, 27 adolescents) enrolled in the German XLH Registry. Age and ...