... lysine, tryp- tophan, valine, leucine, isoleucine, threonine, and phenylalanine. (Five others may be use- ful as supplements ... instead of maximum tolerances that would provide reasonable safety. There is excellent evidence from studies in Canada ...

... enzyme re- placement. For example, a gene for phenylalanine hydroxylase (missing in PKU) might be isolated from ... forecast; we have enough trouble authenti- cating the safety and wide use of acceptable, voluntary ones. Besides ...