Table 1.
Phenylalanine and tyrosine concentrations at diagnosis and before and after institution of phenylalanine supplementation
| Patient 1 | Patient 2 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Additional Phe/day | Diagnosis | 8–364 | Before 8–190 | After 191–1,547 | Diagnosis | 8–364 | 8–190 | Before 8–18 | After 19–364 |
| Phe (μmol/L); median (range) | 45 | 9 (0–39) | 6 (0–19) | 43 (0–119) | 42 | 64 (4–163) | 58 (5–163) | 43 (5–71) | 65 (4–163) |
| Phe <30 (μmol/L) | 88% (15/17) | 100% (10/10) | 33% (32/97) | 9% (9/97) | 10% (6/61) | 33% (1/3) | 9% (8/94) | ||
| Phe <20 (μmol/L) | 71% (12/17) | 100% (10/10) | 15% (15/97) | 6% (6/97) | 5% (3/61) | 33% (1/3) | 5% (5/94) | ||
| Tyr (μmol/L); median (range) | 388 | 292 (133–609) | 253 (152–444) | 298 (132–609) | 391 | 331 (73–728) | 384 (200–728) | 324 (274–526) | 333 (73–728) |
| Tyr >400 (μmol/L) | 24% (4/17) | 10% (1/10) | 11% (11/97) | 31% (30/97) | 49% (30/61) | 33% (1/3) | 31% (29/94) | ||
| Tyr >600 (μmol/L) | 12% (2/17) | 0% (0/10) | 2% (2/97) | 5% (5/97) | 8% (5/61) | 0% (0/3) | 5% (5/94) | ||
| Phe: Tyr ratio; median (range) | 0.12 | 0.03 (0.00–0.08) | 0.02 (0.00–0.05) | 0.15 (0.00–0.38) | 0.11 | 0.21 (0.01–1.07) | 0.16 (0.02–0.35) | 0.13 (0.02–0.16) | 0.21 (0.01–1.07) |
Phe phenylalanine, Tyr tyrosine
Incidence of hypophenylalaninemia and hypertyrosinemia are defined as the percentage of blood samples with phenylalanine concentrations <30 μmol/L or <20 μmol/L and tyrosine concentrations >400 μmol/L or >600 μmol/L, respectively
In patient 1, phenylalanine concentrations could not be quantitated in three samples