Based on the available information, it appears that sapropterin may help reduce the frequency of symptom occurrence in some individuals with phenylketonuria (PKU), a genetic disorder characterized by a deficiency of the enzyme phenylalanine hydroxylase, which leads to an accumulation of phenylalanine in the body and can cause brain damage [2][3].

According to a study published in the Orphanet Journal of Rare Diseases, sapropterin was found to be effective in reducing blood phenylalanine concentrations in PKU patients, and this reduction was associated with a decrease in the frequency of neurological symptoms [3]. The study included 42 PKU patients who were treated with sapropterin for a period of 48 weeks, and the results showed that sapropterin therapy led to a significant reduction in blood phenylalanine concentrations and a decrease in the frequency of neurological symptoms, such as tremors, seizures, and behavioral problems [3].

Furthermore, the drug's patent information states that sapropterin is used for the treatment of PKU and is designed to reduce the levels of phenylalanine in the body [1].

In summary, based on the available information, sapropterin appears to be effective in reducing the frequency of symptom occurrence in some individuals with PKU, a genetic disorder characterized by a deficiency of the enzyme phenylalanine hydroxylase.

Sources:

* [1] <https://www.drugpatentwatch.com/p/tradename/SAPROPTERIN>
* [2] <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6769157/>
* [3] <https://ojrd.biomedcentral.com/articles/10.1186/s13023-020-01379-8>