Novel Synonymous Variant in<i> IL7R</i> Causes Preferential Expression of the Soluble Isoform

<h3>Purpose</h3><p dir="ltr">The interleukin-7 receptor (IL-7R) is primarily expressed on lymphoid cells and plays a crucial role in the development, proliferation, and survival of T cells. Autosomal recessive mutations that disrupt IL-7Rα chain expression give rise to a...

Full description

Saved in:
Bibliographic Details
Main Author: Rafah Mackeh (14151225) (author)
Other Authors: Yasmin El Bsat (19239436) (author), Asha Elmi (9592371) (author), Hani Bibawi (19239439) (author), Mohammed Yousuf Karim (8602092) (author), Amel Hassan (14151231) (author), Bernice Lo (3441317) (author)
Published: 2024
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:<h3>Purpose</h3><p dir="ltr">The interleukin-7 receptor (IL-7R) is primarily expressed on lymphoid cells and plays a crucial role in the development, proliferation, and survival of T cells. Autosomal recessive mutations that disrupt IL-7Rα chain expression give rise to a severe combined immunodeficiency (SCID), which is characterized by lymphopenia and a T<sup>−</sup>B<sup>+</sup>NK<sup>+</sup> phenotype. The objective here was to diagnose two siblings displaying the T<sup>−</sup>B<sup>+</sup>NK<sup>+</sup> SCID phenotype as initial clinical genetic testing did not detect any variants in known SCID genes.</p><h3>Methods</h3><p dir="ltr">Whole genome sequencing (WGS) was utilized to identify potential variants causing the SCID phenotype. Splicing prediction tools were employed to assess the deleterious impact of the mutation. Polymerase Chain Reaction (PCR), Sanger sequencing, flow cytometry, and ELISA were then used to validate the pathogenicity of the detected mutation.</p><h3>Results</h3><p dir="ltr">We discovered a novel homozygous synonymous mutation in the <i>IL7R</i> gene. Our functional studies indicate that this variant is pathogenic, causing exon 6, which encodes the transmembrane domain, to be preferentially spliced out.</p><h3>Conclusion</h3><p dir="ltr">In this study, we identified a novel rare synonymous mutation causing a loss of IL-7Rα expression at the cellular membrane. This case demonstrates the value of reanalyzing genetic data based on the clinical phenotype and highlights the significance of functional studies in determining the pathogenicity of genetic variants.</p><h2>Other Information</h2><p dir="ltr">Published in: Journal of Clinical Immunology<br>License: <a href="https://creativecommons.org/licenses/by/4.0" target="_blank">https://creativecommons.org/licenses/by/4.0</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1007/s10875-024-01688-8" target="_blank">https://dx.doi.org/10.1007/s10875-024-01688-8</a></p>