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

Abstract

Purpose: 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-BH₄) 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.

Methods: 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.

Results: The dose of 6R-BH₄ 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.

Conclusion: The pregnancy had a normal outcome, and so we consider that adaptation of the dose of 6R-BH₄ to the prenatal periods aided a greater efficiency and a lower risk in the treatment of maternal PKU.

Chinese abstract

目的：一名女性在新生儿筛查时被诊断患有苯丙酮尿症（PKU），她的PAH突变为p.V388M/p.I65T，因此接受苯丙氨酸限制疗法，自30岁起开始口服沙丙蝶呤二盐酸盐（6R-BH₄）。本文目的在于描述患者在妊娠过程中的BH₄治疗方法，评估其使用方案。

方法：该患者在34岁时意外妊娠，故其添加了不含苯丙氨酸的物质，包含必需脂肪酸、维生素及微量元素。

结果：6R-BH₄的剂量由500mg/天减至100mg/天，至妊娠28周中止，患者耐受性良好。妊娠期血中苯丙氨酸被顺利控制，且未出现营养素缺乏状况。

结论：该患者妊娠结局正常，所以我们认为在产前期调整6R-BH₄的剂量有助于提高其有效性，且降低母体PKU的治疗风险。

• Maternal phenylketonuria
• phenylketonuria
• sapropterin dihydrochloride
• tetrahydrobiopterin