hrp0089p1-p191 | Multisystem Endocrine Disorders P1 | ESPE2018

SGPL1 Missense Mutation in an Infant with Primary Adrenal Insufficiency (PAI), Congenital Nephrotic Syndrome, Primary Hypothyroidism and Gonadal Failure

Maharaj Avinaash , Wallace Dean , Banerjee Indi , Prasad Rathi , Metherell Lou

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...

hrp0094p1-80 | Fetal Endocrinology and Multisystem Disorders A | ESPE2021

Sphingosine 1- phosphate lyase insufficiency syndrome (SPLIS) as a cause of primary adrenal insufficiency and primary hypogonadism

Kwong Ruth , Maharaj Avinaash , Metherell Lou , Prasad Rathi ,

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 ...

hrp0095fc10.6 | GH and IGFs | ESPE2022

Defects in QSOX2, a novel regulator of STAT5B nuclear import and transcriptional activity, lead to severe post-natal growth restriction

Maharaj Avinaash , Andrews Afiya , Chatterjee Sumana , Hwa Vivian , Storr Helen

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...

hrp0089rfc1.3 | Adrenals & HPA Axis | ESPE2018

Sphingosine-1-Phosphate Lyase (SGPL1) Deficiency is Associated with Mitochondrial Dysfunction

Maharaj Avinaash , Bradshaw Teisha , Williams Jack , Guran Tulay , Braslavsky Debora , Brugger Britta , Metherell Lou , Prasad Rathi

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...

hrp0092fc13.5 | Adrenals and HP Axis | ESPE2019

SGPL1 Deficiency Leads to Downregulation of Key Enzymes Within the Steroidogenic Pathway

Maharaj Avinaash , Meimaridou Eirini , Williams Jack , Güran Tülay , Braslavsky Debora , Metherell Louise , Prasad Rathi

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...

hrp0089lb-p1 | Late Breaking P1 | ESPE2018

A Second Growth Hormone Receptor Pseudoexon Mutation Causing Frameshift and Severe Postnatal Growth Failure

Cottrell Emily , Maharaj Avinaash , Chatterjee Sumana , Grandone Anna , Cirillo Grazia , del Giudice Emanuele Miraglia , Metherell Louise A , Storr Helen L

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...

hrp0094p1-179 | Growth Hormone and IGFs B | ESPE2021

Novel dominant negative GH receptor variants provide important insights into GH receptor physiology

Andrews Afiya , Cottrell Emily , Maharaj Avinaash , Ladha Tasneem , Williams Jack , Metherell Louise A , McCormick Peter J , Storr Helen L ,

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...

hrp0092rfc14.4 | Adrenals and HP Axis | ESPE2019

GHR Transcript Heterogeneity May Explain the Phenotypic Variability in Patients with Homozygous GHR Pseudoexon (6ψ) Mutation

Chatterjee Sumana , Rose Steven J , Mushtaq Talat , Cottrell Emily , Maharaj Avinaash V , Williams Jack , Savage Martin O , Metherell Loiuse A , Storr Helen L

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...

hrp0094p2-287 | Growth and syndromes (to include Turner syndrome) | ESPE2021

Novel LZTR1 mutations in subjects with features of Noonan Syndrome and GH insensitivity negatively regulate GH-induced IGF-I production and hyperactivate GH-induced ERK1/2 activation in response to GH in vitro

Chatterjee Sumana , Romeo Bertola Debora , Agwu Chizo , Maharaj Avinaash , Williams Jack , Cottrell Emily , Shapiro Lucy , Andrews Afiya , Savage Martin O. , Gaston-Massuet Carles , Metherell Louise A. , Storr Helen L. ,

Background: Noonan Syndrome (NS) can overlap clinically and biochemically with growth hormone insensitivity [GHI; short stature (SS), low IGF-I and normal/elevated GH levels]. Mutations in multiple genes regulating RAS/MAPK pathway have been identified in NS including LZTR1 variants. Function of LZTR1 is poorly understood and its role in growth retardation is unknown.Objectives: To functionally characte...

hrp0095p1-110 | Growth and Syndromes | ESPE2022

Characterisation of the first heterozygous missense HMGA2 variant helps delineate the crucial functional roles of a novel growth gene

Cottrell Emily , V. Maharaj Avinaash , Triggs-Raine Barbara , Thanasupawat Thatchawan , Williams Jack , Fujimoto Masanobu , A. Metherell Louise , Hwa Vivian , Klonisch Thomas , Hombach-Klonisch Sabine , L. Storr Helen

Background: Silver Russell syndrome (SRS) is genetically heterogenous and around 30% of patients with clinical SRS have no genetic diagnosis. Mutations in HMGA2 have recently been identified causing growth failure and an SRS-like phenotype. Despite strong evidence of the crucial role of HMGA2 in growth across species, the mechanism of action of HMGA2 in human linear growth is unclear.Objective:...