A 4-day-old male presented with hyperphenylalaninemia in newborn screening. Family history revealed consanguineous parents and a deceased brother with 6-pyruvoyltetrahydropterin synthase (PTPS) deficiency, potentially caused by a homozygous PTS missense variant of unknown significance (NM_000317.3: c.331G>A; p.Ala111Thr). Plasma phenylalanine (Phe) and tyrosine concentrations were 144 and 99 μmol/L (ref int: 20–120 μmol/L), respectively. Transient hyperphenylalaninemia and PTPS deficiency were considered. Neopterin within reference limits and low biopterin were found in urine and dried blood spot (DBS) pterin analyses (Table 1), and PTS gene sequencing was ordered. Hyperphenylalaninemia persisted, ruling out transient hyperphenylalaninemia. Persistent hyperphenylalaninemia with low biopterin, together with family history, was interpreted as being compatible with PTPS deficiency. Since earlier treatment...

中文翻译：

---

通过新生儿筛查转诊的婴儿高苯丙氨酸血症的复杂病因

一名 4 天大的男性在新生儿筛查中出现高苯丙氨酸血症。家族史显示近亲父母和已故兄弟患有 6-丙酮酰四氢蝶呤合酶 (PTPS) 缺乏症，这可能是由意义不明的纯合PTS错义变体 (NM_000317.3: c.331G>A; p.Ala111Thr) 引起的。血浆苯丙氨酸 (Phe) 和酪氨酸浓度分别为 144 和 99 μmol/L（参考文献：20-120 μmol/L）。考虑暂时性高苯丙氨酸血症和 PTPS 缺乏症。在尿液和干血斑 (DBS) 蝶呤分析中发现新蝶呤在参考范围内和低生物蝶呤 (表1），并订购了PTS基因测序。高苯丙氨酸血症持续存在，排除一过性高苯丙氨酸血症。具有低生物蝶呤的持续性高苯丙氨酸血症以及家族史被解释为与 PTPS 缺乏症相容。由于早期治疗...