Impaired EIF2S3 function associated with a novel phenotype of X-linked hypopituitarism with glucose dysregulation

Gregory, Louise C., Ferreira, Carolina B., Young-Baird, Sara K., Williams, Hywel J. ORCID: https://orcid.org/0000-0001-7758-0312, Harakalova, Magdelena, van Haaften, Gijs, Rahman, Sofia A., Gaston-Massuet, Carles, Kelberman, Daniel, GOSgene, Qasim, Waseem, Camper, Sally A., Dever, Thomas E., Shah, Pratik, Robinson, Iain C .A. F. and Dattani, Mehul T. 2019. Impaired EIF2S3 function associated with a novel phenotype of X-linked hypopituitarism with glucose dysregulation. EBioMedicine 42 , pp. 470-480. 10.1016/j.ebiom.2019.03.013

PDF - Published Version Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (1MB)

Abstract

Background The heterotrimeric GTP-binding protein eIF2 forms a ternary complex with initiator methionyl-tRNA and recruits it to the 40S ribosomal subunit for start codon selection and thereby initiates protein synthesis. Mutations in EIF2S3, encoding the eIF2γ subunit, are associated with severe intellectual disability and microcephaly, usually as part of MEHMO syndrome. Methods Exome sequencing of the X chromosome was performed on three related males with normal head circumferences and mild learning difficulties, hypopituitarism (GH and TSH deficiencies), and an unusual form of glucose dysregulation. In situ hybridisation on human embryonic tissue, EIF2S3-knockdown studies in a human pancreatic cell line, and yeast assays on the mutated corresponding eIF2γ protein, were performed in this study. Findings We report a novel hemizygous EIF2S3 variant, p.Pro432Ser, in the three boys (heterozygous in their mothers). EIF2S3 expression was detectable in the developing pituitary gland and pancreatic islets of Langerhans. Cells lacking EIF2S3 had increased caspase activity/cell death. Impaired protein synthesis and relaxed start codon selection stringency was observed in mutated yeast. Interpretation Our data suggest that the p.Pro432Ser mutation impairs eIF2γ function leading to a relatively mild novel phenotype compared with previous EIF2S3 mutations. Our studies support a critical role for EIF2S3 in human hypothalamo-pituitary development and function, and glucose regulation, expanding the range of phenotypes associated with EIF2S3 mutations beyond classical MEHMO syndrome. Untreated hypoglycaemia in previous cases may have contributed to their more severe neurological impairment and seizures in association with impaired EIF2S3.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Medicine
Publisher:	Elsevier
ISSN:	2352-3964
Date of First Compliant Deposit:	13 January 2020
Date of Acceptance:	5 March 2019
Last Modified:	04 May 2023 20:40
URI:	https://orca.cardiff.ac.uk/id/eprint/128292

Citation Data

Cited 25 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item