Severe combined immunodeficiency disease

Severe combined immunodeficiency disease (SCID), Swiss type aglobulinemia, thymic lymphoid tissue dysplasia, and reticular hypoplasia are all severe immunodeficiency diseases. It is characterized by congenital and hereditary B-cell T cell system abnormalities. This group of diseases is autosomal recessive or -linked inheritance. 50% of SCIDs have a positive family history. SCID associated with reticular hypoplasia is caused by defects in primitive hematopoietic stem cells; Swiss-type aglobulinemia is caused by lymphatic stem cell defects; part of SCID is caused by poor T cell differentiation and B cell maturation disorders.