MAJOR CATEGORIES OF COMBINED IMMUNODEFICIENCY
SEVERE COMBINED IMMUNODEFICIENCY (SCID)
SCID comprises a group of inherited diseases characterized by a severe deficit in T-cell development and function with variable defects in B-cell and natural killer or NK cell development. SCID leads to death within the first two years of life, unless patients are rescued by heimatopoetic stem cell transplantation (HSCT). Theses are rare disorders with an estimated frequency between 1 in 50,000 and 1 in 100,000 live births.