Haploinsufficiency of the NF-κB1 Subunit p50 in Common Variable Immunodeficiency

  • Am J Hum Genet. 2015 Sep 3;97(3):389-403. doi: 10.1016/j.ajhg.2015.07.008.
Manfred Fliegauf  1 Vanessa L Bryant  2 Natalie Frede  1 Charlotte Slade  3 See-Tarn Woon  4 Klaus Lehnert  5 Sandra Winzer  1 Alla Bulashevska  1 Thomas Scerri  2 Euphemia Leung  6 Anthony Jordan  7 Baerbel Keller  1 Esther de Vries  8 Hongzhi Cao  9 Fang Yang  9 Alejandro A Schäffer  10 Klaus Warnatz  1 Peter Browett  6 Jo Douglass  11 Rohan V Ameratunga  4 Jos W M van der Meer  12 Bodo Grimbacher  13
Affiliations
  • 1. Center for Chronic Immunodeficiency, University Medical Center Freiburg and University of Freiburg, Freiburg 79108, Germany.
  • 2. Division of Immunology, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia.
  • 3. Division of Immunology, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia; Department of Clinical Immunology and Allergy, Royal Melbourne Hospital, Parkville, VIC 3050, Australia.
  • 4. Department of Virology and Immunology, Auckland City Hospital, Auckland 1023, New Zealand.
  • 5. School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand.
  • 6. Auckland Cancer Society Research Centre and Molecular Medicine and Pathology Department, University of Auckland, Auckland 1142, New Zealand.
  • 7. Department of Clinical Immunology, Auckland City Hospital, Auckland 1023, New Zealand.
  • 8. Department of Pediatrics, Jeroen Bosch Hospital, 's-Hertogenbosch 5200 ME, the Netherlands.
  • 9. BGI-Shenzhen, Shenzhen, 518083, China.
  • 10. NCBI, NIH, Department of Health and Human Services, Bethesda, MD 20894, USA.
  • 11. Division of Immunology, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Clinical Immunology and Allergy, Royal Melbourne Hospital, Parkville, VIC 3050, Australia; Department of Medicine, The University of Melbourne, Parkville, VIC 3010, Australia.
  • 12. Department of Internal Medicine, Radboud University Medical Centre, Nijmegen 6525 HP, the Netherlands.
  • 13. Center for Chronic Immunodeficiency, University Medical Center Freiburg and University of Freiburg, Freiburg 79108, Germany; Institute of Immunity and Transplantation, University College London, London WC1E 6BT, UK. Electronic address: [email protected].
Abstract

Common variable immunodeficiency (CVID), characterized by recurrent infections, is the most prevalent symptomatic antibody deficiency. In ∼90% of CVID-affected individuals, no genetic cause of the disease has been identified. In a Dutch-Australian CVID-affected family, we identified a NFKB1 heterozygous splice-donor-site mutation (c.730+4A>G), causing in-frame skipping of exon 8. NFKB1 encodes the transcription-factor precursor p105, which is processed to p50 (canonical NF-κB pathway). The altered protein bearing an internal deletion (p.Asp191_Lys244delinsGlu; p105ΔEx8) is degraded, but is not processed to p50ΔEx8. Altered NF-κB1 proteins were also undetectable in a German CVID-affected family with a heterozygous in-frame exon 9 skipping mutation (c.835+2T>G) and in a CVID-affected family from New Zealand with a heterozygous frameshift mutation (c.465dupA) in exon 7. Given that residual p105 and p50—translated from the non-mutated alleles—were normal, and altered p50 proteins were absent, we conclude that the CVID phenotype in these families is caused by NF-κB1 p50 haploinsufficiency.