The One Gene/One Enzyme Hypothesis Beadle and Tatum's 1941
Breakthrough Gene therapy for inherited diseases may be one of
the most beneficial results of the biotechnology revolution.
Many such diseases, including hemophilia and cystic fibrosis,
result when a single defective gene causes the production of a
non-functional protein. Gene therapy attempts to replace the
defective genes with normal ones, allowing the patient to
produce the necessary protein and function normally. The first
human gene therapy test (still in progress) involves a girl
suffering from severe immune problems due to a defective gene
for the enzyme adenosine deaminase (ADA). Doctors have attempted
to treat her by removing some of her bone marrow cells,
inserting functional ADA genes into these cells, and then
putting the "corrected" cells back in place. The basis of gene
therapy rests on our understanding of the relationship between
genes and proteins - between genotype and phenotype. The concept
that a gene is responsible for the product