Severe combined immune deficiency disease due to a deficiency of the e
nzyme adenosine deaminase is a rare disease. However, it has been used
as a prototype disease for the development of a variety of treatment
modalities that are currently applied in more frequent diseases. For e
xample, allogeneic bone marrow transplantation and stem cell gene ther
apy have been used for adenosine deaminase deficiency before being app
lied in other more frequent diseases. In the present paper, the develo
pment of bone marrow transplantation and stem cell gene therapy, as we
ll as treatment with purified enzyme, for adenosine deaminase deficien
cy are discussed.