
<ArticleTitle>Familial <prot>CD8</prot> deficiency due to a mutation in the <prot><prot>CD8</prot> alpha</prot> gene.</ArticleTitle>
<AbstractText><prot>CD8</prot> glycoproteins play an important role in both the maturation and function of MHC class I-restricted T lymphocytes. A 25-year-old man, from a consanguineous family, with recurrent bacterial infections and total absence of <prot>CD8</prot>(+) cells, was studied. Ab deficiencies and ZAP-70 and TAP defects were ruled out. A missense mutation (gly90--ser) in both alleles of the immunoglobulin domain of the <prot><prot>CD8</prot> alpha</prot> gene was shown to correlate with the absence of <prot>CD8</prot> expression found in the patient and two sisters. Conversely, high percentages of <prot>CD4</prot>(-)<prot>CD8</prot>(-)<prot>TCR alpha beta</prot>(+) T cells were found in the three siblings. A novel autosomal recessive immunologic defect characterized by absence of <prot>CD8</prot>(+) cells is described. These findings may help to further understanding of the role of <prot>CD8</prot> molecules in human immune response.</AbstractText>
