尿蝶呤分析在四氢生物蝶呤缺乏症筛查中的应用

Urinary pterin analysis in screening of tetrahydrobiopterin def iciency

目的 通过尿蝶呤分析从高苯丙氨酸血症 (HPA)患儿中筛检出四氢生物蝶呤 (BH4)缺乏症。方法 采用高效液相层析仪对 96例HPA患儿进行尿新蝶呤和生物蝶呤分析 ,并对尿蝶呤异常者结合BH4负荷试验以辅助诊断。结果 筛检出 11例 6 丙酮酰四氢蝶呤合成酶缺乏所致的BH4缺乏症 ,患儿尿新蝶呤 (N)与生物蝶呤 (B)值之比极度增高 (N/B :197± 2 5 0 ) ,B百分率极低为 (1.0±0 8) %。其中 4例口服BH4后 ,血苯丙氨酸浓度由 (72 0～ 12 0 0 ) μmol/L降至 (12 0～ 2 40 ) μmol/L。 结论 BH4缺乏症在HPA中发生率约 12 % 。

Objective To screen out the tetrahydrobiopterin def iciency in patients with hyperphenylalaninemia by urinary pterin analysis. Methods Analysis of urinary neopterin (N) and biopterin (B) was done in 96 patients with hyperphenylalaninemia by high performance liquid chromatography. Combined BH4 loading test was performed for patients with abnormal urinary pterin profiles. Results Eleven patients were diagnosed as ha ving BH4 deficiency caused by 6 pyruvoyl tetrahydrobiopterin synthase deficiency. They had a much high N/B ratio(N/B:197±250) and a very low B percentage (1.0±0.8)%. Blood phenylalanine levels were decreased from (720 1 200) μmol/L to (120 240) μmol/L after taking BH4 tablets in 4 of 11 patients. Conclusion The incidence of BH4 deficiency among hyperphenylalaninemia is about 12%. Analysis of urinary pterin is feasible and effective in screening of BH4 deficiency.