Abstract
Hyper-immunoglobulin M (IgM) syndrome (HIGM) is a rare primary immunodeficiency characterized by elevated or normal IgM and absent or markedly decreased amounts of IgG, IgA and IgE. The X-linked form (HIGM1) is the most common type and is caused by mutations in the gene for CD40L, a T-cell surface molecule required for T-cell driven immunoglobulin class switching by B cells. In the present study we have identified a patient with X-linked hyper-IgM who failed to express CD40L on the cell surface of CD4+ T lymphocytes. Sequence analysis of CD40L genomic DNA showed no mutations. CD40L mRNA was absent and sequence analysis of the CD40L promotor revealed a mutation at position -123 from the transcription start site. The mutation in the promotor region likely contributed to the decreased transcription as demonstrated by a luciferase reporter assay.
Original language | English (US) |
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Pages (from-to) | 497-501 |
Number of pages | 5 |
Journal | Immunology |
Volume | 120 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2007 |
Keywords
- CD40L
- Hyper-IgM
- Immunodeficiency
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology