Atypical X-Linked Severe Combined Immunodeficiency Due to Possible Spontaneous Reversion of the Genetic Defect in T Cells

Abstract

X-linked severe combined immunodeficiency is a recessive hereditary disease characterized by severe and persistent infections starting in the first months of life and associated with diarrhea and failure to thrive.1 Affected infants almost invariably present with an absence of T cells and natural killer cells, normal or elevated B-cell counts, and hypogammaglobulinemia. This disease is rapidly fatal without bone marrow transplantation.2 The disease locus has been mapped to Xq12–13,3 and the genetic defect identified as a mutation of the γ chain of the interleukin-2 receptor,4 which has been cloned and was recently renamed the common γ (γc) chain because of . . .