ESPE Abstracts

Background: Growth Hormone Insensitivity (GHI) is characterised by short stature and functional IGF-I deficiency associated with normal/elevated GH levels. Marked genetic and phenotypic heterogeneity exist, and heritable defects in GH-IGF-I axis genes/associated pathways account for mild-moderate to severe GHI cases. We report twin brothers from a non-consanguineous kindred who present with short stature and bi-allelic mutations in QSOX2 encoding the nuclear m...

Background: Loss of function mutations in SGPL1 have previously been described by our group in association with a multisystemic disorder encompassing PAI and nephrotic syndrome. SGPL1 encodes, sphingosine 1-phosphate lyase (SGPL1), which irreversibly binds sphingosine 1-phosphate (S1P) and commits it to the final degradative step in sphingolipid metabolism. SGPL1 is therefore a major modulator of S1P signalling. Several sphingolipid intermediates such as cera...

Sphingosine 1-phosphate lyase insufficiency syndrome (SPLIS) was described in 2017 as a novel condition affecting sphingolipid metabolism, with bi-allelic loss of function mutations in SGPL1. There is a multisystemic phenotype including steroid resistant nephrotic syndrome and primary adrenal insufficiency (PAI) and to a lesser extent ichthyosis, neurological disease and lymphopenia. Hypogonadism is described amongst some affected patients. To interrogate the steroid ...

Background: Loss of function mutations in SGPL1, a key component of sphingolipid metabolism, are associated with accumulation of sphingolipid intermediates giving rise to a multisystemic disease incorporating primary adrenal insufficiency (PAI) and progressive renal and neurological disease. Sphingolipids are implicated in mitochondrial apoptosis via induction of mitochondrial outer membrane permeabilization, cytosolic release of inter-membranal cytochrome c and activ...

Background: Defects in growth hormone (GH) action account for a substantial percentage of endocrine causes of growth restriction but are frequently unrecognised due to wide clinical and biochemical variability. We report five probands from three families who present with short stature, features of atypical growth hormone insensitivity (GHI), immune dysfunction, atopic eczema, and gastrointestinal pathology associated with novel recessive variants in a new gene...

Introduction: Growth restriction (GR) comprises ~50% of new patient referrals to paediatric endocrine clinics with <20% receiving a clear diagnosis. Enhanced genetic testing and stratification leading to tailored clinical care is a fundamental need. Whole-genome sequencing (WGS) was offered to patients recruited to the 100,000 Genomes Project (100 KGP), leading to new diagnoses in ~25% of all rare disease participants. The analysis pipeline uses disease-spe...

Background: SGPL1 deficiency is associated with a pathological accumulation of sphingolipid intermediates and a multi-systemic condition incorporating primary adrenal insufficiency. Sphingolipid intermediates such as ceramide, sphingosine and sphingosine 1-phosphate are postulated to act as modulators of the steroidogenic pathway, often acting as second messengers altering downstream expression of steroid responsive transcriptional elements. Ceramide and sphin...

Background: Growth Hormone Insensitivity (GHI) is usually caused by mutations in the Growth Hormone receptor (GHR). Patients present with short stature associated with high GH and low IGF-I levels and often have midfacial hypoplasia (typical Laron syndrome facial features). Our centre previously described the first GHR pseudoexon mutation (42700896A>G, c. 618+792A>G). The inclusion of this 108bp pseudoexon is predicted to lead to in-frame insertion of...

Background: Growth hormone insensitivity (GHI) encompasses normal/elevated growth hormone (GH), low IGF-I levels and growth restriction. Non-classical/mild-moderate GHI is an emerging entity which is poorly characterised, and, in many subjects, the underlying cause is unclear. Heterozygous dominant negative (DN) variants located in the intracellular/transmembrane domain of the GH receptor (GHR) cause a ‘non-classical’ GHI phenotype.<p class="abst...

Background: Noonan syndrome (NS) is caused by variants in multiple genes regulating the RAS/MAPK signalling cascade. NS can present with growth failure associated with growth hormone insensitivity (GHI; low IGF-I and normal/elevated GH levels). Variants in LZTR1 lead to NS, although the interaction of LZTR1 with the RAS/MAPK and the GH-IGF-1 pathways remain to be elucidated.Objectives: To gain insights into the ...