ESPE Abstracts

Background: Hypophosphatasia (HPP) is a rare, inherited metabolic disease caused by loss-of-function mutations in the gene encoding tissue nonspecific alkaline phosphatase (TNSALP), resulting in hypomineralisation of bone. HPP presenting <6 months of age is often lethal due to respiratory insufficiency, with survival of 42% at 1 year. Asfotase alfa, a human recombinant TNSALP replacement, promotes bone mineralisation, with survival of 95% at 1 year in infants with HPP....

Introduction: Vosoritide increases growth in children with achondroplasia aged 5–18 years (Savarirayan et al, Genet Med, 2021). We recently reported results from a phase 2, randomized, double-blind, placebo-controlled study (111-206) in young children with achondroplasia aged 3 months–5 years Here we present results from an open-label extension study (111-208) spanning up to 4 years of treatment in the children aged 2-5 years at study star...

Introduction: Klinefelter syndrome (KS) is most common sex chromosomal aneuploidy in males. The typical clinical features are tall stature with long extremities, small testis, and learning disabilities. Three M syndrome is an extremely rare genetic disorder characterized by short stature, craniofacial abnormality and skeletal malformations. We report a unique case of short stature in KS due to three M syndrome.Case: A 9-...

Background: Primary ovarian insufficiency (POI) is genetically mediated in up to 30% of cases. Many genes associated with POI have roles in early ovary developmental processes, including meiosis.Objectives: We investigated the genetic mechanism underlying early-onset POI in three young women presenting with absent puberty: two sisters from a consanguineous pedigree and a third unrelated proband.<st...

Background: Persistent Müllerian duct syndrome (PMDS) is a Disorder of Sex Development (DSD) caused by mutations in genes encoding anti-Müllerian hormone (AMH) or its type II receptor (AMHR2) with autosomal recessive transmission. Objective: To report a case of transverse testicular ectopia (TTE), associated with PMDS, initially presented as an obstructed inguinal hernia.Case presentation: An 18- days- old male infant, wi...

Background: Bone age (BA) is commonly used in pediatrics to define skeletal maturity for medical and non-medical purposes. Normal range is represented by 2 standard deviations (SDs) above and below the mean. A BA greater than &pm;2 SDs from the chronological age (CA) is considered abnormal. BA in achondroplasia (ACH) has not been fully characterized; calculation is challenging given difficulties in comparing x-rays with standard radiographs if using the Greuli...

Background: ACH, the most common short-limbed skeletal dysplasia, is characterized by defective endochondral ossification resulting from gain-of-function mutations in the fibroblast growth factor receptor 3 (FGFR3) gene, a negative regulator of endochondral bone formation. Current treatment options are non-targeted, ineffective, or painful interventions aimed at preventing or treating complications. Infigratinib is an orally bioavailable and selective...

Background: ACH is the most common short-limbed skeletal dysplasia, affecting between 1 in 15,000 to 1 in 30,000 live births. Children and adults with ACH have disproportionate short stature, with a final height of approx. 131 cm for males and 124 cm for females. People with ACH are prone to significant co-morbidities, including obstructive sleep apnea, chronic otitis media with conductive hearing loss, spinal stenosis, and a propensity towards obesity. In som...

Background: Achondroplasia (ACH), the most common short-limbed skeletal dysplasia, is characterized by impaired endochondral ossification resulting from gain-of-function pathogenic variants in the fibroblast growth factor receptor 3 (FGFR3) gene, a negative regulator of endochondral bone growth. People with ACH are at risk for several significant co-morbidities, including brainstem compression due to foramen magnum stenosis, sleep-disordered breathing, chronic...

Objectives: Several different pathogenic mechanisms may converge on a final common pathway to produce the phenotype of delayed pubertal timing. In our cohort of patients with familial self-limited delayed puberty (DP) we have demonstrated mutations in IGSF10 leading to mis-regulation of the embryonic migration of GnRH neurons (Howard et al, EMBO MM 2016). We aimed to discover novel genetic mutations in pathways regulating GnRH neuronal migration and developme...