Linus Pauling: There are several ways that we might handle this [phenylketonuria and other diseases
caused by enzyme dysfunction].
One, in which it's being handled now, is by diet - it's not too satisfactory.
Another way would be to make a synthetic enzyme, which was introduced in the bloodstream,
say, perhaps in a little capsule through which the blood flowed. This has not yet
been achieved, but it might be.
Another way might be, of course, to make preparations of the enzyme and inject them.
This is a possibility, perhaps not a very likely one.
Still another would be to make preparations of the gene itself. There is even the
possibility of making a sort of synthetic gene, which might be smaller than the actual
gene, and get it into the cells of the defective person, such that this replacement
gene would take over the job of manufacturing the enzyme.