remedy this malabsorption problem. Children with ADA deficiency have low-grade 
and chronic infectious respiratory problems. Partial recovery of the immune 
system would help prevent or slow deterioration in their pulmonary function. 
If the patient were fully reconstituted he/she would be able to avoid the side 
effects of therapies medically indicated because of their disease (such as 
hearing loss from the use of aminoglycosides to treat serious bacterial 
Infections). The Immunological dysfunction in these patients can also manifest 
Itself In autoimmune disorders: again, restoration of even partial Immunity 
may reduce or alleviate these problems. Immune surveillance is another 
Important role that the body's immune system performs. Children with 
ADA(-) SCID have a higher risk of developing lymphomas than the general 
population. This risk should be reduced as well. A child with ADA deficiency 
that undergoes totally successful gene therapy should be able to lead a normal 
life and have a normal expected lifespan: partial correction should allow a 
more normal life. 
Even If gene therapy were a total failure, the risks associated with the 
attempt should be low and the patient would not be precluded from attempts with 
alternative therapies, such as a mis-matched bone marrow transplantation, to 
treat their disease. 
(2) Adverse effects . The patient may not receive any benefit from 
attempted gene therapy. While the attempt may not directly harm the patient, 
nonetheless he/she would not be receiving alternative forms of therapy (except, 
of course, supportive care) during this time. The delay in attempts to 
reconstitute the Immune system during this wait could expose the patient to the 
risks normally associated with the disorder. The longer the patient Is at risk 
the higher the probability of morbidity and mortality. 
The patient could suffer from the procedure itself. The multiple bone 
Recombinant DNA Research, Volume 12 [67] 
