Mutation in the TCRalpha subunit constant gene (TRAC) leads to a human immunodeficiency disorder characterized by a lack of TCRalphabeta+ T cells.
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Morgan NV, Goddard S, Cardno TS, McDonald D, Rahman F, Barge D, Ciupek A, Straatman-Iwanowska A, Pasha S, Guckian M, Anderson G, Huissoon A, Cant A, Tate WP, Hambleton S, Maher ER
Mutation in the TCRalpha subunit constant gene (TRAC) leads to a human immunodeficiency disorder characterized by a lack of TCRalphabeta+ T cells.
J Clin Invest. 2011 Feb;121(2):695-702. doi: 10.1172/JCI41931. Epub 2011 Jan 4.
- PubMed ID
- 21206088 [ View in PubMed]
- Abstract
Inherited immunodeficiency disorders can be caused by mutations in any one of a large number of genes involved in the function of immune cells. Here, we describe two families with an autosomal recessive inherited immunodeficiency disorder characterized by increased susceptibility to infection and autoimmunity. Genetic linkage studies mapped the disorder to chromosomal region 14q11.2, and a homozygous guanine-to-adenine substitution was identified at the last base of exon 3 immediately following the translational termination codon in the TCRalpha subunit constant gene (TRAC). RT-PCR analysis in the two affected individuals revealed impaired splicing of the mRNA, as exon 3 was lost from the TRAC transcript. The mutant TCRalpha chain protein was predicted to lack part of the connecting peptide domain and all of the transmembrane and cytoplasmic domains, which have a critical role in the regulation of the assembly and/or intracellular transport of TCR complexes. We found that T cells from affected individuals were profoundly impaired for surface expression of the TCRalphabeta complex. We believe this to be the first report of a disease-causing human TRAC mutation. Although the absence of TCRalphabeta+ T cells in the affected individuals was associated with immune dysregulation and autoimmunity, they had a surprising level of protection against infection.