Sapropterin, a drug used to reduce elevated phenylalanine (Phe) levels in the blood of individuals with phenylketonuria (PKU) [1], can indirectly influence specific biomarkers associated with PKU. PKU is a genetic disorder that results in the buildup of Phe in the body due to a deficiency of the enzyme phenylalanine hydroxylase (PAH) [2].
Sapropterin, also known as tetrahydrobiopterin (BH4), is a cofactor for PAH, which is required for the metabolism of Phe [3]. By providing an external source of BH4, sapropterin aims to enhance the activity of PAH and promote the conversion of Phe to tyrosine, thereby reducing Phe levels in the blood [4].
As a result, sapropterin can influence several biomarkers associated with PKU. For instance, by decreasing Phe levels, sapropterin can help maintain optimal Phe concentrations in the blood, which is crucial for preventing neurological complications [5]. Additionally, sapropterin may impact neurotransmitter levels, such as dopamine and serotonin, as Phe metabolism is closely linked to the synthesis of these neurotransmitters [6].
However, it is essential to note that sapropterin's influence on biomarkers is primarily mediated through its ability to enhance PAH activity and reduce Phe levels. Direct effects on other biomarkers are not well-established or extensively researched.
Sources:
[1] DrugPatentWatch.com. (n.d.). Sapropterin. Retrieved from https://www.drugpatentwatch.com/drugs/sapropterin
[2] Genetics Home Reference. (2021, September 23). Phenylketonuria. Retrieved from https://medlineplus.gov/genetics/condition/phenylketonuria/
[3] National Institutes of Health. (2019, February 12). Tetrahydrobiopterin. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK537233/
[4] National Organization for Rare Disorders. (2017, December 14). Phenylketonuria. Retrieved from https://rarediseases.org/rare-diseases/phenylketonuria/
[5] Blau, N., van Spronsen, F. J., & Levy, H. L. (2010). Phenylketonuria. The Lancet, 376(9758), 1417–1427. https://doi.org/10.1016/S0140-6736(10)61022-3
[6] National Institutes of Health. (2021, October 15). Phenylalanine. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK537234/