X-linked recessive TLR7 deficiency in ~1% of men under 60 years old with life-threatening COVID-19

Autosomal inborn errors of type I IFN immunity and autoantibodies against these cytokines underlie at least 10% of critical COVID-19 pneumonia cases. We report very rare, biochemically deleterious X-linked TLR7 variants in 16 unrelated male individuals aged 7 to 71 years (mean: 36.7 years) from a cohort of 1,202 male patients aged 0.5 to 99 years (mean: 52.9 years) with unexplained critical COVID-19 pneumonia. None of the 331 asymptomatically or mildly infected male individuals aged 1.3 to 102 years (mean: 38.7 years) tested carry such TLR7 variants (p = 3.5 × 10-5). The phenotypes of five hemizygous relatives of index cases infected with SARS-CoV-2 include asymptomatic or mild infection (n=2, 5 and 38 years), or moderate (n=1, 5 years), severe (n=1, 27 years), or critical (n=1, 29 years) pneumonia. Two boys (aged 7 and 12 years) from a cohort of 262 male patients with severe COVID-19 pneumonia (mean: 51.0 years) are hemizygous for a deleterious TLR7 variant. The cumulative allele frequency for deleterious TLR7 variants in the male general population is < 6.5x10-4 We also show that blood B cell lines and myeloid cell subsets from the patients do not respond to TLR7 stimulation, a phenotype rescued by wild-type TLR7 The patients' blood plasmacytoid dendritic cells (pDCs) produce low levels of type I IFNs in response to SARS-CoV-2. Overall, X-linked recessive TLR7 deficiency is a highly penetrant genetic etiology of critical COVID-19 pneumonia, in about 1.8% of male patients below the age of 60 years. Human TLR7 and pDCs are essential for protective type I IFN immunity against SARS-CoV-2 in the respiratory tract. Funding: The Laboratory of Human Genetics of Infectious Diseases is supported by the Howard Hughes Medical Institute, Rockefeller University; the St. Giles Foundation; the NIH (R01AI088364), the National Center for Advancing Translational Sciences (NCATS); NIH Clinical and Translational Science Award (CTSA) program (UL1TR001866); a Fast Grant from Emergent Ventures; Mercatus Center at the George Mason University; the Yale Center for Mendelian Genomics and the GSP Coordinating Center funded by the National Human Genome Research Institute (NHGRI) (UM1HG006504 and U24HG008956); the Meyer Foundation; the JPB Foundation; the French National Research Agency (ANR) under the “Investments for the Future” program (ANR-10-IAHU-01) and the Integrative Biology of Emerging Infectious Diseases Laboratory of Excellence (ANR-10-LABX-62-IBEID); the French Foundation for Medical Research (FRM) (EQU201903007798); the FRM and ANR GENCOVID project, the ANRS-COV05, ANR GENVIR (ANR-20-CE93-003), and ANR AABIFNCOV (ANR-20-CO11-0001) projects; the European Union’s Horizon 2020 Research and Innovation Program under grant agreement no. 824110 (EASI-genomics). The French COVID Cohort study group was sponsored by INSERM and supported by the REACTing consortium and by a grant from the French Ministry of Health (PHRC 20-0424). The Cov-Contact Cohort was supported by the REACTing consortium, the French Ministry of Health, and the European Commission (RECOVER WP 6). The Neurometabolic Diseases Laboratory received funding from the European Union’s Horizon 2020 Research and Innovation Program (EasiGenomics grant no. 824110 COVID-19/PID12342). A.P., R.P.d.D., C.R.-G., and C.F. were funded by Instituto de Salud Carlos III (COV20_01333 and COV20_01334), the Spanish Ministry of Science and Innovation (RTC-2017-6471-1; AEI/FEDER, UE), Fundación DISA (OA18/017), and Cabildo Insular de Tenerife (CGIEU0000219140 and “Apuestas científicas del ITER para colaborar en la lucha contra la COVID-19”). The laboratories of G.N. and A.N. were supported by a grant awarded to Regione Lazio (PROGETTI DI GRUPPI DI RICERCA 2020) no. A0375-2020-36663, GecoBiomark. A. Amara’s laboratory was supported by ANR under the “Investments for the Future” program (ANR-10-IAHU-01), the Integrative Biology of Emerging Infectious Diseases Laboratory of Excellence (ANR-10-LABX-62-IBEID), the FRM (EQU202003010193), ANR (ANR-20-COVI-000 project IDISCOVR and ANR-20-CO11-0004 project FISHBP), and the University of Paris (Plan de Soutien Covid-19: RACPL20FIR01-COVID-SOUL). This work was supported, in part, by the Division of Intramural Research, NIAID, NIH (grants 1ZIAAI001265 to H.C.S. and ZIA AI001270 to L.D.N.). The G.C. laboratory was supported by the Italian Ministry of Health (grant COVID-2020-12371617) and the intramural COVID Host Genetics program. The J.L.F. laboratory was supported, in part, by the Coopération Scientifique France-Colciencias (ECOS-Nord/COLCIENCIAS/MEN/ICETEX; 806-2018) and Colciencias contract 713-2016 (no. 111574455633). The V.S. laboratory was supported by ANR DENDRISEPSIS (ANR-17-CE15-0003) and ANR APCOD (ANR-17-CE15-0003-01), a Fast Grant from the Mercatus Center, FRM, University of Paris PLAN D’URGENCE COVID19. The N.M. laboratory was supported by Sidra Medicine (SDR400048) and the Qatar National Research Fund (grant No. NPRP9-251-3-045)