| Codon 408 (20% of PKU cases) | Codon 280 (2% of PKU cases) | ||||
|---|---|---|---|---|---|
| Normal | Mutant | Normal | Mutant | ||
| Length of PAH protein | 452 amino acids | 452 amino acids | 452 amino acids | 452 amino acids | |
| DNA at codon | ...CGG... | ...TGG... | ...GAA... | ...AAA... | |
| ...GCC... | ...ACC... | ...CTT... | ...TTT... | ||
| mRNA at codon | ...CGG... | ...UGG... | ...GAA... | ...AAA... | |
| Amino acid at codon | Arginine | Tryptophan | Glutamic acid | Lysine | |
| Active PAH enzyme? | Yes | No | Yes | No | |