16 
Dr. MoGarrity asked whether diseases exist in which the intervention must 
occur within the first few weeks of a patient's life. Would such diseases 
present a problem if the total review process requires three or four 
months? 
Dr. Anderson said some diseases should be treated at birth or even pre- 
natal ly. He said the length of time required for review might be a poten- 
tial problem for such patients in future applications. In the initial 
cases, however, human subjects will be selected only after the protocols 
are reviewed and approved. One of the first cases will probably be severe 
combined inmune deficiency disease (SCID) caused by ADA deficiency. There 
are only about 50 reported families in the world with this disorder. While 
these patients are rare, they are ideally suited to be the first subjects 
of gene therapy, because they can be cured by bone marrow transplantation . 
Mr. Rifkin said he was concerned because the working group had chosen to 
discuss only somatic cell gene therapy at this tine, and to ignore the 
issues associated with germline human gene therapy. He said previous 
studies had dealt with both somatic and germline applications in the same 
context . 
Mr. Rifkin felt it was inappropriate to treat these two categories sepa- 
rately because "there might be some correlation between certain somatic 
gene experiments and seme effects on the germline or the reproductive 
cells." He asked vhether long-term effects of somatic cell experiments on 
the patient's germline could be detected. Mr. Rifkin said if any possi- 
bility exists that these experiments might affect the patient's germline, 
then it would be "inappropriate to move ahead knowing that speculation is 
possible and trying to isolate these two categories." 
Dr. Walters said the task of RAC and the working group is to respond to 
individual proposals on a case-by-case basis and not to engage in a general 
discussion of global issues. The President's Commission has already dis- 
cussed global issues. Dr. Walters said the working group will ask investiga- 
tors to supply data from laboratory experiments to exclude the very slight 
possibility somatic cell gene therapy might have an effect on sperm or egg 
cells . 
Dr. Rapp said the possibility a gene inserted into seme other portion of 
the subject's body would transfer to the germ cells is extremely lew. 
Dr. Joklik said numerous experiments have been performed on various animal 
species from mice to chickens to insects. In no case had the introduced 
DNA been found to transfer to germ cells. Dr. Joklik said that at this 
time the probability of such an occurence is so lew it is not a concern. 
Dr. Lardy said many current therapies have profound effects on the germline. 
He did not feel this consideration was unique to human gene therapy. 
Dr. Henry Miller of the FDA agreed various therapies have side effects. He 
said it is unreasonable to fixate on the effects to gametes to the exclusion 
of effects on cardiac or liver tissues. 
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