Abstract:

X-linked severe combined immunodeficiency (X-SCID) is the most common type of severe combined immunodeficiency disease. The typical immunological feature is the complete absence of mature T cells and NK cells with normal or elevated B cell numbers. The clinical features are recurrent and severe opportunistic infections from early infancy. The patients often have early onset, severe clinical manifestations and poor prognosis. Without prompt diagnosis and treatment, most patients die within the age of two. Hematopoietic stem cell transplantation is the preferred treatment and has a very high survival rate (>90 %) if HLA-matched sibling donors are used. However, when alternative donors are used, the success rate and survival rate are often lower. Gene therapy has been developed as an alternative therapy.

Key words: X-linked severe combined immunodeficiency, hematopoietic stem cell transplantation, gene therapy, gene editing