Abstract
Objective: Sapropterin dihydrochlorid represents a new option of therapy for the part of patients with phenylketonuria/hyperphenylalaninemia (PKU/HPA). The efficiency of this synthetic form of cofactor tetrahydrobiopterin (BH4) depends on genotype and residual activity of the enzyme phenylalaninhydroxylase (PAH).
The aim of the study was testing the selected patients for responsivity and allowing some of them to continue this new form of treatement. Methods: The study included 32 children, who were examinated by one-day or two-day BH4 test (dose 20 mg/kg/day of sapropterin).
The measurement of phenylalanine (Phe) serum concentration was done at regular intervals. The test positivity was defined by the decrease in Phe serum concentration by the minimum of 30% of its original level.
Results: In 15 children BH4 test was positive. The treatment using sapropterin had been gradually implemented for 11 children, at this time 6 of them continue the treatment.
No side effects have been noted, concentrations of Phe are stable and mostly in therapeutic optimum. Two patients are entirely without diet, other patients under mild dietary restriction.
Conclusion: The treatment using sapropterin is expensive, but it allows patients to return to ordinary life without limitation and risks associated with diet restriction and noncompliance.