X-linked SCID(γc-chain deficiency)

X-linked SCID, accounting for about 50-60% of SCID cases, is caused by IL-2 receptor γ chain mutations, which lead to very low numbers of T cells and NK cells, whereas B cells are present in high numbers. The B cells are immature and defective. IL-2 receptor (IL-2R) γ -chain (CD25) deficiency has also been reported. The γ chain of the receptor forms part of the receptor also for IL-2, -4, -7, -9, and -15, affecting the differentiation and growth of lymphocytes. The γ chain consists of an extracellular domain with WS motif, transmembrane region, as well as intracellular domain with Box1 and Box2 regions. Some 150 different mutations distributed in all the domains have been determined.

Alternative names

Scidx; XSCID

Scid, x-linked

Cytokine receptor common gamma chain

Agammaglobulinemia, swiss type

Thymic epithelial hypoplasia

Immunodeficiency 4; IMD4


  • Combined B and T cell immunodeficiencies
    • T-B+ SCID




#300400 Severe Combined Immunodeficiency, X-linked; SCIDX1

*308380 Interleukin 2 Receptor , Gamma; IL2RG

Cross references

Phenotypically related immunodeficiencies

IDR factfile for JAK3 deficiency


1/200,000 births/year