A new case of maternal phenylketonuria treated with sapropterin dihydrochloride (6R-BH4)

A woman with phenylketonuria (PKU) was diagnosed through neonatal screening, her PAH mutation was p.V388M/p.I65T, for which she received treatment with phenylalanine restriction, and was administered oral sapropterin dihydrochloride (6R-BH(4)) from the age of thirty. The purpose of this article is to describe the treatment with BH4 during her pregnancy and to evaluate a plan for its use.

The patient had an unplanned pregnancy at 34 years of age, for which she received a phenylalanine-free supplement enriched with essential fatty acids, vitamins and trace elements.

The dose of 6R-BH(4) was reduced from 500 mg/day to 100 mg/day until its suspension in the 28th week of gestation, and was well tolerated. Blood phenylalanine control was easily accomplished during this pregnancy, and no nutritional deficiency was seen.

The pregnancy had a normal outcome, and so we consider that adaptation of the dose of 6R-BH(4) to the prenatal periods aided a greater efficiency and a lower risk in the treatment of maternal PKU.