Hyperphenylalaninemia due to a deficiency of biopterin. A variant form of phenylketonuria.
Hyperphenylalaninemia due to a deficiency of biopterin. A variant form of phenylketonuria.
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生物蝶呤缺乏导致的高苯丙氨酸血症。
DOI：
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发表时间：
1978
影响因子：
158.5
通讯作者：
S. Pueschel
中科院分区：
文献类型：
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作者：
S. Kaufman;S. Berlow;G. Summer;S. Milstien;J. Schulman;S. Orloff;S Spielberg;S. Pueschel
我们研究了一名患有苯丙酮尿症的儿童的肝脏苯丙氨酸羟基化系统的成分，尽管早期饮食控制了血液苯丙氨酸水平升高，但该儿童仍表现出严重的神经功能障碍。苯丙氨酸羟化酶、二氢蝶啶还原酶和二氢叶酸还原酶活性正常。相比之下，肝脏中羟基化辅因子四氢生物蝶呤的水平仅为正常水平的 10%。除了这种肝缺陷之外，生物蝶呤样化合物的血清和尿液水平也较低，并且血清生物蝶呤不会像正常人和苯丙酮尿症受试者那样因苯丙氨酸负荷而增加。通过体内氚释放测定测定，该儿童的苯丙氨酸羟化酶活性为正常值的 2.3%。这些结果表明，该儿童患有一种变异形式的苯丙酮尿症——继发于生物蝶呤生物合成缺陷的功能性苯丙氨酸羟基化系统的缺陷。
We studied the components of the hepatic phenylalanine hydroxylating system in a child with phenylketonuria who showed substantial neurologic impairment despite early dietary control of elevated blood phenylalanine levels. Phenylalanine hydroxylase, dihydropteridine reductase and dihydrofolate reductase activities were normal. In contrast the level of hydroxylation cofactor, tetrahydrobiopterin, in liver was only 10 per cent of normal. In addition to this hepatic deficiency, serum and urinary levels of biopterin-like compounds were low, and the serum biopterin did not increase in response to a phenylalanine load as it does in normal and phenylketonuric subjects. The phenylalanine hydroxylase activity in this child, as determined by an in vivo tritium-release assay, was 2.3 per cent of the normal value. These results indicate that the child suffers from a variant form of phenylketonuria--a deficiency of a functional phenylalanine hydroxylating system secondary to a defect in biosynthesis of biopterin.