ABSTRACT
If either of the RAG genes is knocked out by homologous recombination in mice, B-cell and T-cell development is completely abolished and the mice have severe combined immunodeficiency. Mutations in RAG-1 and RAG-2 have also been found in cases of human SCID. Certain missense mutations in the RAG genes, however, result in partial enzymatic activity, and this gives rise to an interesting immunodeficiency disease called Omenn syndrome.
