Related gene: CD8A
Inheritance pattern: Autosomal recessive
CD8 deficiency is an extremely rare autosomal recessive disorder due to homozygous variants in the CD8A gene. CD8 is a T cell receptor (TCR) accessory molecule that interacts with the major histocompatibility complex (MHC). CD8 is found on cytotoxic T cells and NK cells.
Individuals with CD8 deficiency have a range of clinical phenotypes from asymptomatic to recurrent sinopulmonary infections beginning later in childhood. CD4+ T cell, B cell, and NK cell percentages and absolute counts are normal, but CD8+ T cells are absent. There is no published data regarding therapy for these patients and management is directed toward infectious complications and may include Ig replacement therapy.