Differential diagnosis of tetrahydrobiopterin deficiency
| Autor: | Alois Niederwieser, Hans-Christoph Curtius, Alberto Ponzone |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
medicine.medical_specialty
Phenylketonurias Phenylalanine Diagnosis Differential Hyperphenylalaninemia Internal medicine Genetics medicine Humans GTP Cyclohydrolase Sepiapterin reductase Amino Acid Metabolism Inborn Errors Tetrahydrobiopterin deficiency Genetics (clinical) medicine.diagnostic_test Chemistry Pteridines Tetrahydrobiopterin medicine.disease Dihydropteridine Reductase Biopterin Endocrinology Liver biopsy medicine.drug |
| Zdroj: | Journal of Inherited Metabolic Disease. 8:34-38 |
| ISSN: | 1573-2665 0141-8955 |
| DOI: | 10.1007/bf01800657 |
| Popis: | Six hundred and seventy-three children (483 newborns and 190 older selected children) were screened for tetrahydrobiopterin (BH4) deficiency by HPLC of urine pterins and BH4 load test. One patient with GTP cyclohydrolase I deficiency, 36 patients with dihydrobiopterin synthetase (DHBS) deficiency (of which six were in the newborn and 30 in the older children) and 14 with dihydropteridine reductase deficiency (DHPR) were found. All 37 patients with defective BH4 biosynthesis responded to a BH4 load by lowering of the elevated serum phenylalanine concentration but four of 14 patients with DHPR deficiency did not. Measurement of DHPR activity in blood spots on Guthrie cards is recommended. Since subvariants of patients with BH4 deficiency exist, homovanillic acid, 5-hydroxyindole acetic acid, pterins, phenylalanine, and tyrosine in cerebrospinal fluid should be measured for diagnosis and the control of therapy. The activity of the phosphate-eliminating enzyme (a key enzyme in BH4 biosynthesis and part of "DHBS") was measured in human liver and activities of approx. 1 n U (mg protein)-1 were found. In the liver biopsy of a patient with DHBS deficiency no activity (less than 3% of controls) was demonstrated. |
| Databáze: | OpenAIRE |
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