Historical perspective: tyrosine and maternal phenylketonuria, welcome news

Autophagy induction by tetrahydrobiopterin deficiency

“…56,57 In fact, treatment of pregnant PKU patients with tyrosine has been reported to exhibit some alleviation of the symptoms. 55 Our study demonstrating the activation of autophagic pathway by mTORC1 inactivation in PKU-affected patients with BH 4 deficiency may provide some additional insight into therapeutics that could be used to improve the symptoms of diseases associated with BH 4 deficiency.…”

“…[54][55][56][57] Low concentrations of tyrosine in both the fetus and pregnant mother have been implicated as an important from BH 4 -responsive PKU patients with a high level of plasma phenylalanine (>400 μmol/L) contained insufficient amounts of S6K and phosphorylated S6K. Interestingly, diminished levels of tubulin were also observed in lymphocytes from BH 4 -responsive PKU patients.…”

Phenylalanine hydroxylase mutations and phenylalanine-tyrosine metabolism in heterozygotes for phenylalanine hydroxylase deficiency

“…The recognized correlation between genotype and metabolic phenotype in subjects affected by PAH de ciency (4, 23) is a further stimulus to investigate this issue in heterozygotes. The elucidation of Tyr synthesis and metabolism in heterozygotes for PAH de ciency could help in optimizing dietary supplementation in pregnant carriers to prevent a possible secondary damage to the foetus with homozygous PAH de ciency (24). Finally, a better identication of the carrier state through a biochemical test could help in genetic counselling while checking the status of the PAH locus in a person who is planning to have children with a carrier of a PAH mutation or an affected patient, even if more precise reference values are needed.…”