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...

hrp0095p1-101 | GH and IGFs | ESPE2022

A rare heterozygous IGFI variant causing impaired IGF-I cleavage and postnatal growth failure: a novel disease mechanism with insights into IGF-I physiology

Cottrell Emily , Andrews Afiya , Williams Jack , Chatterjee Sumana , Edate Sujata , A. Metherell Louise , Hwa Vivian , L. Storr Helen

Background: Pathogenic IGFI gene mutations causing childhood growth failure are rare. Only 5 autosomal recessive mutations, one IGFI copy number variant and 2 heterozygous frameshift mutations are reported. Heterozygous missense IGFI mutations have not previously been described.Objectives: To identify and functionally characterise a novel missense IGFI variant in a patient with postnat...

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...

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...