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ABSTRACT: Introduction
Loss-of-function TLR7 variants have been recently reported in a small number of males to underlie strong predisposition to severe COVID-19. We aimed to determine the presence of these rare variants in young men with severe COVID-19.Methods
We prospectively studied males between 18 and 50 years-old without predisposing comorbidities that required at least high-flow nasal oxygen to treat COVID-19. The coding region of TLR7 was sequenced to assess the presence of potentially deleterious variants.Results
TLR7 missense variants were identified in two out of 14 patients (14.3%). Overall, the median age was 38 (IQR 30-45) years. Both variants were not previously reported in population control databases and were predicted to be damaging by in silico predictors. In a 30-year-old patient a maternally inherited variant [c.644A>G; p.(Asn215Ser)] was identified, co-segregating in his 27-year-old brother who also contracted severe COVID-19. A second variant [c.2797T>C; p.(Trp933Arg)] was found in a 28-year-old patient, co-segregating in his 24-year-old brother who developed mild COVID-19. Functional testing of this variant revealed decreased type I and II interferon responses in peripheral mononuclear blood cells upon stimulation with the TLR7 agonist imiquimod, confirming a loss-of-function effect.Conclusions
This study supports a rationale for the genetic screening for TLR7 variants in young men with severe COVID-19 in the absence of other relevant risk factors. A diagnosis of TLR7 deficiency could not only inform on treatment options for the patient, but also enables pre-symptomatic testing of at-risk male relatives with the possibility of instituting early preventive and therapeutic interventions.
SUBMITTER: Solanich X
PROVIDER: S-EPMC8343010 | biostudies-literature | 2021
REPOSITORIES: biostudies-literature
Solanich Xavier X Vargas-Parra Gardenia G van der Made Caspar I CI Simons Annet A Schuurs-Hoeijmakers Janneke J Antolí Arnau A Del Valle Jesús J Rocamora-Blanch Gemma G Setién Fernando F Esteller Manel M van Reijmersdal Simon V SV Riera-Mestre Antoni A Sabater-Riera Joan J Capellá Gabriel G van de Veerdonk Frank L FL van der Hoven Ben B Corbella Xavier X Hoischen Alexander A Lázaro Conxi C
Frontiers in immunology 20210723
<h4>Introduction</h4>Loss-of-function <i>TLR7</i> variants have been recently reported in a small number of males to underlie strong predisposition to severe COVID-19. We aimed to determine the presence of these rare variants in young men with severe COVID-19.<h4>Methods</h4>We prospectively studied males between 18 and 50 years-old without predisposing comorbidities that required at least high-flow nasal oxygen to treat COVID-19. The coding region of <i>TLR7</i> was sequenced to assess the pres ...[more]