Fig. 1.

Phenylalanine concentrations and supplementation (upper), tyrosine concentrations and ratios of blood phenylalanine-tyrosine concentrations (middle), and growth parameters as well as protein intake (lower) in patient 1 during the first year (a) and the first 4 years of life (b) and in patient 2 during the first year of life (c). The vertical line indicates the start of phenylalanine supplementation