Cd8 Deficiency, Familial

A number sign (#) is used with this entry because CD8 deficiency is caused by mutation in the CD8-alpha gene (CD8A; 186910).

Clinical Features

De la Calle-Martin et al. (2001) reported a 25-year-old man with a history of recurrent bacterial and viral infections since age 5 years. Immunoglobulin levels and IgG subclasses were normal, but he had total absence of CD8-positive T cells, both CD3+ and CD3- (see, e.g., 186740). Percentages and absolute numbers of CD4 (186940)-positive T cells, B cells, and natural killer (NK) cells were all normal. The patient was born from consanguineous Spanish Gypsy parents and was the fourth of 9 sibs. Two younger asymptomatic sisters also had total absence of CD8-positive T cells.

Molecular Genetics

In a patient with CD8-positive T cell deficiency, de la Calle-Martin et al. (2001) identified a homozygous gly90-to-ser mutation in the CD8A gene (G90S; 186910.0001). His asymptomatic sisters with absence of CD8 expression were also homozygous for the G90S mutation; the parents were heterozygous.