A novel mutation in the CD40 ligand gene in a Chinese boy with X-linked hyper-IgM syndrome.

Abstract

X-linked hyper-IgM Syndrome (XHIGM) is caused by a mutation of CD40 ligand (CD40L), which is normally expressed on activated CD4+ T cells and is responsible for immunoglobulin class switching. A 7-year-old boy with recurrent sino-pulmonary infections since the age of 3 months had normal CD3+, CD4+, CD8+T lymphocytes, and CD19+B lymphocytes and NK cells, but significantly elevated IgM and extremely decreased IgG and IgA. Sequencing of genomic DNA revealed that the patient had a 34 base deletion in intron 3 and exon 4 of CD40L(g.8172_8205del34bp), which lead to the entire deletion of exon 4 in cDNA (c.347_409del63bp, i.e.,exon 4 skipping) and an in-frame deletion of 21 amino acids in CD40L protein. Moreover, the patient had negligible CD40L expression on activated CD3+CD8-T lymphocytes. His mother and sister were carriers of the CD40L mutation. Our studies demonstrated a novel mutation in CD40L, which, to our knowledge, has not been reported previously.

• Authors: Po-Ning Liu, Hong Li, Qiang Li, Zhong-Wei Yin, Chen-Yan Zhou, Ming-Yan Jiang, Xia Guo
• Journal: Asian Pacific journal of allergy and immunology (Asian Pac J Allergy Immunol) Vol. 32 Issue 3 Pg. 270-4 (Sep 2014) ISSN: 0125-877X [Print] Thailand
• PMID: 25268346 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Immunoglobulins
• CD40 Ligand

Topics

• Asian People
• CD40 Ligand (blood, genetics, immunology)
• Child
• Exons
• Gene Expression Regulation (genetics, immunology)
• Humans
• Hyper-IgM Immunodeficiency Syndrome, Type 1 (blood, genetics, immunology)
• Immunoglobulins (blood, immunology)
• Lymphocytes (immunology, metabolism)
• Male
• Mutation