ESPE Abstracts

Background: Folate and cobalamin are needed for synthesis of methionine, a substrate of methylation in epigenetic, and epigenomic pathways. Methyl donor deficiency (MDD) leads to hyperhomocysteinemia, which has been related to osteoporosis in humans and disruption of epiphyseal cartilage and bone development in rodents. Recent studies have revealed evidence for association between 25(OH)D3 and homocysteine levels, however, underlying mechanisms remain elusive.<p...

Objectives: The homozygous GHR pseudoexon (6ψ) mutation leads to aberrant splicing of the GHR gene with clinical and biochemical heterogeneity. We investigated whether the phenotypic variability could be explained by transcript heterogeneity i.e. ratio of abnormal (6ψ GHR) to normal (WT GHR) transcripts and/or the presence of concurrent defects in other short stature (SS) genes.Methods: 6&#968...

Background: Although growth hormone (GH) and the GH releasing hormone receptor (GHRHR) are known as etiologic factors in non-syndromic isolated growth hormone deficiency (IGHD), very few mutations have been identified in this rare condition (accounting for only 6–12.5% and 0–6.7% of IGHD cases depending on studies). The functional consequences of the identified variants have rarely been assessed.Objective and hypotheses: To assess the contribut...

Background and Aim: Vertebral fractures (VF) in children with acute lymphoblastic leukemia (ALL) are often symptomatic and impairing life quality. Prevalence of children with VF at ALL diagnosis has been reported as 16% with peak incidence occurring during the first year after diagnosis and a 6-year cumulative incidence of 32.5%. Moreover, only 15.8% of these patients will have vertebral reshaping 24 months after ALL diagnosis. Additionally, 23% of ALL survivo...

Background: Individuals with the ultra-rare genetic disorder FOP experience progressive heterotopic ossification. Median age at diagnosis is 5 years; patients are supported by multiple specialties. Most patients become immobilised by the third decade of life, requiring lifelong assistance. We characterise AADA use as an indicator of disease severity in younger individuals with FOP enrolled in a 36-month, prospective, global NHS (NCT02322255).<p class="abst...

Background: FOP is an ultra-rare, severely disabling genetic disorder characterised by progressive heterotopic ossification. The median age at diagnosis is 5 years and patients are supported by multiple specialties. We describe normal long bone growth changes and incidence of bone abnormalities in participants with FOP aged <18 years in a 3-year, prospective, global NHS (NCT02322255).Methods: Individuals with FOP age...

Introduction: Our Centre is an international referral centre for genetic analysis of children with short stature (SS) and features of GH/IGF-1 resistance. Following candidate gene and whole exome sequencing, diagnoses for ~50% patients remained elusive. Copy number variation (CNV) has not previously been investigated in GH/IGF-1 resistance and we hypothesised that CNVs contribute to the phenotype in our undiagnosed cohort.Experimental Design and Methodol...

Background: Mutations in the gene encoding LHX4, a homeodomain-containing factor with two LIM domains, are responsible for dominant hypopituitarisms with incomplete penetrance and variable expressivity. To date, only 14 unambiguous LHX4 mutations have been reported. Among those cases, 12 had an absent or ectopic posterior pituitary (EPP) and/or an abnormal sella turcica.Objective and hypotheses: To i) assess the contribution of LHX4 in combined pituitary...

Background: FOP is an ultra-rare, severely disabling genetic disorder characterised by progressive heterotopic ossification (HO) following flare-ups. The median age at diagnosis is 5 years, and patients are managed by multiple specialties. No study to date has provided a longitudinal evaluation of FOP. Final data are presented for participants, aged <25 years, enrolled in the first 36-month, prospective, global natural history study of FOP (NCT02322255).</...

Purpose: Isolated growth hormone deficiency (IGHD) is a rare condition mainly caused by mutations in GH1. The aim of this study was to assess the contribution of GHRHR mutations to IGHD in a very large cohort of patients.Methods: All GHRHR coding exons and flanking intronic regions were sequenced in 312 unrelated patients with non-syndromic IGHD. Functional consequences of all newly identified missense variants were assessed <e...