Mutations in the gene for the IL-7 receptor result in T–B+NK+ severe combined immunodeficiency disease

Recently, two SCID (severe combined immunodeficiency disease) patients with greatly diminished T cells but normal or increased numbers of B and NK cells (T–B+NK+ SCID) were found to have mutations in the gene for the IL-7 receptor. This has established a major role for IL-7-receptor-dependent signaling in T cell development in humans and probably explains the diminished T cell numbers seen in patients with X-linked SCID or SCID that results from Jak3-deficiency.