Caused by mutations in the gene encoding interleukin-2 receptor gamma chain (IL 2RG) that results in a lack of response to common gamma chain dependent cytokines, and absence of T-cell and natural killer-cell development, and impairment of B-cell function.
Death from community acquired or opportunistic infection usually occurs before one year of age unless patients undergo allogeneic hematopoietic stem cell transplant.
Immunologic defect with this disorder obviates the need for preparative treatment before transplantation
Allogeneic HSCT with matching sibling donor is associated with an 85-90% overall survival rate.
Transplantation with mismatched related, managed unrelated, or umbilical cord donors or transplantation in patients with ongoing infection so associated with lower rates of survival including graft versus host disease.
Patients with protracted infection at the time of HSCT have a mortality rate of approximately 50%.