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Jung-Klawitter S, Kuseyri Hübschmann O. Analysis of Catecholamines and Pterins in Inborn Errors of Monoamine Neurotransmitter Metabolism-From Past to Future. Cells 2019; 8:cells8080867. [PMID: 31405045 PMCID: PMC6721669 DOI: 10.3390/cells8080867] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/02/2019] [Accepted: 08/04/2019] [Indexed: 12/13/2022] Open
Abstract
Inborn errors of monoamine neurotransmitter biosynthesis and degradation belong to the rare inborn errors of metabolism. They are caused by monogenic variants in the genes encoding the proteins involved in (1) neurotransmitter biosynthesis (like tyrosine hydroxylase (TH) and aromatic amino acid decarboxylase (AADC)), (2) in tetrahydrobiopterin (BH4) cofactor biosynthesis (GTP cyclohydrolase 1 (GTPCH), 6-pyruvoyl-tetrahydropterin synthase (PTPS), sepiapterin reductase (SPR)) and recycling (pterin-4a-carbinolamine dehydratase (PCD), dihydropteridine reductase (DHPR)), or (3) in co-chaperones (DNAJC12). Clinically, they present early during childhood with a lack of monoamine neurotransmitters, especially dopamine and its products norepinephrine and epinephrine. Classical symptoms include autonomous dysregulations, hypotonia, movement disorders, and developmental delay. Therapy is predominantly based on supplementation of missing cofactors or neurotransmitter precursors. However, diagnosis is difficult and is predominantly based on quantitative detection of neurotransmitters, cofactors, and precursors in cerebrospinal fluid (CSF), urine, and blood. This review aims at summarizing the diverse analytical tools routinely used for diagnosis to determine quantitatively the amounts of neurotransmitters and cofactors in the different types of samples used to identify patients suffering from these rare diseases.
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Affiliation(s)
- Sabine Jung-Klawitter
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany.
| | - Oya Kuseyri Hübschmann
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany
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Hamuro A, Tachibana D, Misugi T, Katayama H, Ozaki K, Fujino Y, Yoshihiro N, Shintaku H, Koyama M. Serum Biopterin and Neopterin Levels as Predictors of Empty Follicles. JAPANESE CLINICAL MEDICINE 2015; 6:29-34. [PMID: 26568687 PMCID: PMC4631162 DOI: 10.4137/jcm.s32018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 08/30/2015] [Accepted: 09/07/2015] [Indexed: 02/06/2023]
Abstract
OBJECTIVE This study measured serum and follicular fluid (FF) levels of biopterin, neopterin, vascular endothelial growth factor (VEGF), and macrophage colony-stimulating factor (M-CSF) in patients receiving mild ovarian stimulation for oocyte retrieval. PATIENTS AND METHODS Infertile patients who underwent ovarian stimulation were divided into the following: Group 1, no oocyte retrieval (n = 12), and Group 2, retrieval of more than four oocytes (n = 13). Median total gonadotropin dose in both groups was 150 IU. Biopterin and neopterin levels were measured using high-performance liquid chromatography. VEGF and M-CSF levels were measured by enzyme-linked immunosorbent assay. RESULTS Compared to Group 2, serum and FF levels of neopterin and VEGF and serum levels of M-CSF were significantly increased, and serum and FF levels of biopterin were significantly decreased in Group 1 (P < 0.05 each). CONCLUSION Biopterin and neopterin levels showed similar differences in FF and serum of patients with empty follicles. Decreased biopterin and increased neopterin in serum could predict poor oocyte retrieval.
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Affiliation(s)
- Akihiro Hamuro
- Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Daisuke Tachibana
- Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Takuya Misugi
- Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Hiroko Katayama
- Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Koji Ozaki
- Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | | | | | - Haruo Shintaku
- Department of Pediatrics, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Masayasu Koyama
- Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, Osaka, Japan
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Kuhara T, Ohse M, Inoue Y, Shinka T, Okano Y, Shintaku H, Hongou K, Miyawaki T, Morinobu W, Tamai H, Omura K. Urinary metabolic profile of phenylketonuria in patients receiving total parenteral nutrition and medication. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:3167-3172. [PMID: 19718778 DOI: 10.1002/rcm.4236] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nutrition and drugs are main environmental factors that affect metabolism. We performed metabolomics of urine from an 8-year-old patient (case 1) with epilepsy and an 11-year-old patient (case 2) with malignant lymphoma who was being treated with methotrexate. Both patients were receiving total parenteral nutrition (TPN). We used our diagnostic procedure consisting of urease pretreatment, partial adoption of stable isotope dilution, gas chromatography/mass spectrometry (GC/MS) measurement and target analysis for 200 analytes including organic acids and amino acids. Surprisingly, their metabolic profiles were identical to that of phenylketonuria. The neopterin level was markedly above normal in case 1, and both neopterin and biopterin were significantly above normal in case 2. Mutation analysis of genomic DNA from case 1 showed neither homozygosity nor heterozygosity for phenylalanine hydroxylase deficiency. The metabolic profiles of both cases were normal when they were not receiving TPN. TPN is presently prohibited for individuals who have inherited disorders that affect amino acid metabolism. Although the Phe content of the TPN was not the sole cause of the PKU profile, its effect, combined with other factors, e.g. specific medication or possibly underlying diseases, led to this metabolic abnormality. The present study suggests that GC/MS-based metabolomics by target analysis could be important for assuring the safety of the treatments for patients receiving both TPN and methotrexate. Metabolomic profiling, both before and during TPN, is useful for determining the optimal nutritional formula not only for neonates, but also for young children who are known heterozygotes for metabolic disorders or whose status is unknown.
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Affiliation(s)
- Tomiko Kuhara
- Division of Human Genetics, Medical Research Institute, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan.
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Leuzzi V, Carducci CA, Carducci CL, Pozzessere S, Burlina A, Cerone R, Concolino D, Donati MA, Fiori L, Meli C, Ponzone A, Porta F, Strisciuglio P, Antonozzi I, Blau N. Phenotypic variability, neurological outcome and genetics background of 6-pyruvoyl-tetrahydropterin synthase deficiency. Clin Genet 2009; 77:249-57. [PMID: 20059486 DOI: 10.1111/j.1399-0004.2009.01306.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This study aimed to investigate the clinical variability and factors implied in the outcome of 6-pyruvoyl-tetrahydropterin synthase deficiency (PTPSd). Biochemical and clinical phenotype, treatment variables, and 6-pyruvoyl-tetrahydropterin synthase (PTS) genotype, were explored retrospectively in 19 Italian patients (12 males and 7 females, aged 4 months to 33 years). According to the level of biogenic amines in cerebrospinal fluid (CSF) at the diagnosis, the patients were classified as mild (6) (normal level) or severe (13) (abnormal low level) form (MF and SF, respectively). Blood Phe ranged from 151 to 1053 micromol/l in MF (mean +/- SD: 698 +/- 403) and 342-2120 micromol/l in SF (mean +/- SD: 1175 +/- 517) (p = 0.063). Patients with MF showed a normal neurological development (a transient dystonia was detected in one), while all SF patients except one presented with severe neurological impairment and only four had a normal neurological development. The outcome of the SF was influenced by the precocity of the treatment. Serial CSF examinations revealed a decline of 5-hydroxyindolacetic acid in MFs and an incomplete restoration of neurotransmitters in SFs: neither obviously affected the prognosis. PTS gene analysis detected 17 different mutations (seven so far unreported) (only one affected allele was identified in three subjects). A good correlation was found between genotype and clinical and biochemical phenotype. The occurrence of brain neurotransmitter deficiency and its early correction (by the therapy) are the main prognostic factors in PTPSd.
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Affiliation(s)
- V Leuzzi
- Department of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
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Pearl PL, Capp PK, Novotny EJ, Gibson KM. Inherited disorders of neurotransmitters in children and adults. Clin Biochem 2005; 38:1051-8. [PMID: 16298354 DOI: 10.1016/j.clinbiochem.2005.09.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Revised: 09/16/2005] [Accepted: 09/21/2005] [Indexed: 11/24/2022]
Abstract
Inherited disorders of neurotransmitters are a group of neurometabolic syndromes attributable to a primary disturbance of neurotransmitter metabolism or transport. This is an enlarging group of recognized disorders requiring specialized diagnostic procedures for detection. This review considers clinical disorders of biopterin, catecholamines, serotonin, glycine, pyridoxine, and GABA metabolism. Newly described syndromes such as cerebral folate deficiency and pyridoxal-5-phosphate dependency are included. The disorders of the metabolic pathways of biopterin, catecholamines, and serotonin are linked due to their common synthetic components. Glycine encephalopathy represents an enlarging phenotype related to abnormalities of the glycine degradative cleavage system. Both pyridoxine and pyridoxal-5-phosphate dependency need to be considered in refractory neonatal seizures. The most common disorder of GABA metabolism is SSADH deficiency, which has a broad phenotype of mental retardation, epilepsy, ataxia, and hyporeflexia and which invokes the combined problems of elevated brain GABA and GHB.
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Affiliation(s)
- Phillip L Pearl
- Department of Neurology, Children's National Medical Center, George Washington University School of Medicine and Health Sciences, Washington, DC 22052, USA
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6
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Chien YH, Chiang SC, Huang A, Lin JM, Chiu YN, Chou SP, Chu SY, Wang TR, Hwu WL. Treatment and outcome of Taiwanese patients with 6-pyruvoyltetrahydropterin synthase gene mutations. J Inherit Metab Dis 2001; 24:815-23. [PMID: 11916314 DOI: 10.1023/a:1013984022994] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Ten cases of tetrahydrobiopterin (BH4) deficiency were identified in 1,337,490 newborns screened in a Chinese population in Taiwan. The high incidence of BH4 deficiency in the Taiwanese population may be explained by a founder effect, since all of the patients revealed 6-pyruvoyltetrahydropterin synthase gene mutations, and grouping N52S and P87S mutations together constituted 88.9% of the disease alleles. BH4 supplementation with restriction of high-protein foods gave control of plasma phenylalanine within normal range, and levodopa itself prevented seizure. However, the average intelligence quotient (IQ) score of these patients was only 76 +/- 14 (56-98). Statistically, the age of starting medication, including 5-hydroxytryptophan (5-HTP), was inversely correlated to IQ scores of these patients. We suggest the combination of BH4, levodopa and 5-HTP as the standard protocol to commence the treatment of BH4 deficiency as early as possible, although prenatal brain damage could have existed.
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Affiliation(s)
- Y H Chien
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei
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Bonafé L, Thöny B, Leimbacher W, Kierat L, Blau N. Diagnosis of Dopa-responsive Dystonia and Other Tetrahydrobiopterin Disorders by the Study of Biopterin Metabolism in Fibroblasts. Clin Chem 2001. [DOI: 10.1093/clinchem/47.3.477] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Background: Dopa-responsive dystonia (DRD) and tetrahydrobiopterin (BH4) defects are inherited disorders characterized by monoamine neurotransmitter deficiency with decreased activity of one of the BH4-metabolizing enzymes. The aim of the study was to determine the utility of cultured skin fibroblasts for the diagnosis of these diseases.
Methods: Neopterin and biopterin production and GTP cyclohydrolase I (GTPCH) activity were measured in cytokine-stimulated fibroblasts; 6-pyruvoyltetrahydropterin synthase (PTPS), sepiapterin reductase (SR), and dihydropteridine reductase (DHPR) activities were measured in unstimulated fibroblasts. We examined 8 patients with DRD, 3 with autosomal recessive GTPCH deficiency, 7 with PTPS deficiency, 3 with DHPR deficiency, and 49 controls (35 fibroblast and 14 amniocyte samples).
Results: Fibroblasts from patients with DRD and autosomal recessive GTPCH deficiency showed reduced GTPCH activity (15.4% and 30.7% of normal activity, respectively) compared with controls (P <0.001). Neopterin production was very low and biopterin production was reduced in both disorders. PTPS- and DHPR-deficient cells showed no enzyme activities; in PTPS deficiency the pattern of pterin production was typical (neopterin, 334–734 pmol/mg; controls, 18–98 pmol/mg; biopterin, 0 pmol/mg; controls, 154–303 pmol/mg). Reference values of all enzyme activities and pterin production were measured in fibroblasts and also in amniocytes for prenatal diagnosis.
Conclusions: Cultured skin fibroblasts are a useful tool in the diagnosis of BH4 deficiencies. Intracellular neopterin and biopterin concentrations and GTPCH activity in cytokine-stimulated fibroblasts are particularly helpful in diagnosing patients with DRD.
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Affiliation(s)
- Luisa Bonafé
- Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University of Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
| | - Beat Thöny
- Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University of Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
| | - Walter Leimbacher
- Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University of Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
| | - Lucja Kierat
- Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University of Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
| | - Nenad Blau
- Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University of Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
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Abstract
We detected a case of 6-pyruvoyl tetrahydropterin synthase (PTPS) deficiency during a neonatal mass screening and considered the differentiation and treatment of the peripheral form of PTPS deficiency. Although single treatment of BH4 had been started, because of the lowered biopterin (B) value, elevated neopterin (N) value, and N/B ratio in the cerebrospinal fluid (CSF), the peripheral form was judged negative and combined treatment with L-dopa and 5-hydroxy tryptophan (5-HTP) was started. Follow-up study will be necessary to confirm the diagnosis of PTPS deficiency.
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Affiliation(s)
- H Shintaku
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3, Asahimachi, Abeno-ku, 545-8585, Osaka, Japan.
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Oppliger T, Thöny B, Kluge C, Matasovic A, Heizmann CW, Ponzone A, Spada M, Blau N. Identification of mutations causing 6-pyruvoyl-tetrahydropterin synthase deficiency in four Italian families. Hum Mutat 2000; 10:25-35. [PMID: 9222757 DOI: 10.1002/(sici)1098-1004(1997)10:1<25::aid-humu4>3.0.co;2-l] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
6-Pyruvoyl-tetrahydrobiopterin synthase (PTPS) is involved in tetrahydrobiopterin (BH4) biosynthesis, the cofactor for various enzymes including the hepatic phenylalanine hydroxylase. Inherited PTPS deficiency leads to BH4 depletion, causes hyperphenylalaninemia, and requires cofactor replacement therapy for treatment. We previously isolated the human PTPS cDNA and recently characterized its corresponding gene, PTS. Here we developed PCR-based mutation analysis with newly designed primers to detect genomic alterations and describe five mutations, four of which are novel, in the PTS gene of four Italian families with affected individuals. The mutant alleles found included three missense mutations (T67M, K129E, D136V), a previously described triplet deletion (delta V57), and a single c-3-->g transversion in the 3'-acceptor splice site of intron 1, leading to cryptic splice site usage that resulted in a 12 bp deletion (mutant allele delta (K29-S32)). Except for K129E, all mutant alleles were inactive and/or unstable proteins, as shown by recombinant expression and Western blot analysis of patients' fibroblasts. The PTPS-deficient patient with the homozygous K129E allele had transient hyperphenylalaninemia, did not depend on BH4 replacement therapy, and showed normal PTPS immunoreactivity, but no enzyme activity in primary fibroblasts and red blood cells. In contrast to its inactivity in these cells, the K129E mutant was 2-3 fold more active than wild-type PTPS when transfected into COS-1 or the human hepatoma cell line Hep G2. K129E appears thus as a mutant PTPS whose activity depends on the cell type.
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Affiliation(s)
- T Oppliger
- Department of Pediatrics, University of Zürich, Switzerland
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Blau N, Scherer-Oppliger T, Baumer A, Riegel M, Matasovic A, Schinzel A, Jaeken J, Thöny B. Isolated central form of tetrahydrobiopterin deficiency associated with hemizygosity on chromosome 11q and a mutant allele of PTPS. Hum Mutat 2000; 16:54-60. [PMID: 10874306 DOI: 10.1002/1098-1004(200007)16:1<54::aid-humu10>3.0.co;2-c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
6-Pyruvoyl-tetrahydropterin synthase (PTS or PTPS) is involved in tetrahydrobiopterin (BH(4)) biosynthesis, the cofactor for various enzymes including the aromatic amino acid hydroxylases. Inherited PTPS deficiency is a heterogeneous disease with different phenotypes leading to BH(4) depletion. The severe form of PTPS deficiency causes hyperphenylalaninemia and monoamine neurotransmitter deficiency, whereas the mild form gives rise to hyperphenylalaninemia only. From 228 patients with PTPS deficiency at least 32 different mutant alleles have been identified on its corresponding gene, located on chromosome 11q22.3-q23.3. Here we describe a new allele from a child with PTPS deficiency who exhibited a mild but transient form of hyperphenylalaninemia, yet was deficient in CSF monoamines. The patient was found to carry, on her genomic DNA and cDNA, a homozygous A>G transition, leading to PTPS codon alteration Tyr99 to Cys (Y99C). The mother and several members of the maternal family were carriers of the Y99C allele, also verified by the reduced PTPS enzyme activity in erythrocytes. By cytogenetic, molecular, and FISH analyses, a de novo deletion spanning from 11q14 to 11q23.3 on the patient's paternal chromosome was mapped, establishing hemizygosity of the Y99C allele. The PTPS mutation observed in this patient generates a novel phenotype with an apparently isolated central form of BH(4) deficiency.
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Affiliation(s)
- N Blau
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zürich, Switzerland
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Single-Step Mutation Scanning of the 6-Pyruvoyltetrahydropterin Synthase Gene in Patients with Hyperphenylalaninemia. Clin Chem 1999. [DOI: 10.1093/clinchem/45.12.2102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
AbstractBackground: Deficiency of 6-pyruvoyltetrahydropterin synthase (PTPS) is a recessively inherited disorder that leads to depletion of 5,6,7,8-tetrahydrobiopterin, the obligatory cofactor for hydroxylation of phenylalanine, tyrosine, and tryptophan. A marker for neonatal detection of PTPS deficiency is hyperphenylalaninemia (HPA). Molecular analysis would provide a simple and reliable means for distinguishing PTPS deficiency from other potential causes of HPA.Methods: We developed a method based on PCR in combination with denaturing gradient gel electrophoresis (DGGE) that rapidly scans the six coding sequences and all splice sites of the PTPS gene (PTS) for mutations. This method was used to examine the status of the PTS gene in control samples with known PTS mutations and in five patients with PTPS deficiency.Results: Two features of the PTS gene posed particular problems in relation to DGGE analysis: the very high GC content of exon 1, and a 15-bp poly(dT) stretch in the acceptor splice site of intron 1. Both problems were solved by special design of amplification primers. PCR and DGGE conditions were adjusted to allow simultaneous analysis of all six regions of the PTS gene. Using this one-step approach, all control mutations were readily resolved. Among the five PTPS patients, four mutations were identified, including IVS1-3C→G, IVS2-7T→A, V57del, and V97M (289G→A). The IVS1-3C→G mutation was shown by reverse transcription-PCR analysis to produce multiple splice variants.Conclusions: We have established a fast and reliable screening method for detection of mutations and small deletions/insertions in the PTS gene. This method should be useful for rapid diagnosis of PTPS deficiency in newborns with HPA.
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Linscheid P, Schaffner A, Blau N, Schoedon G. Regulation of 6-pyruvoyltetrahydropterin synthase activity and messenger RNA abundance in human vascular endothelial cells. Circulation 1998; 98:1703-6. [PMID: 9788822 DOI: 10.1161/01.cir.98.17.1703] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The nitric oxide synthase cofactor tetrahydrobiopterin (BH4) is involved in the regulation of endothelium-dependent vascular functions mediated by nitric oxide. Vascular endothelial cells synthesize and secrete large amounts of BH4 on cytokine activation. There is scant knowledge about molecular mechanisms of cytokine-triggered BH4 production in endothelial cells. METHODS AND RESULTS Pteridine production, mRNA expression of GTP cyclohydrolase (GTPCH) and 6-pyruvoyltetrahydropterin synthase (PTPS) (both key enzymes of BH4 biosynthesis), and PTPS activity were studied in human umbilical vein endothelial cells (HUVECs) exposed to inflammatory cytokines. BH4 levels were </=140-fold enhanced on treatment of HUVECs with combined interferon-gamma/tumor necrosis factor-alpha/interleukin-1 (IFN/TNF/IL-1). Specific PTPS activity was approximately 3-fold higher in cytokine-treated HUVECs than in untreated cells. Reverse-transcription/limiting-dilution polymerase chain reaction analysis showed that in response to IFN/TNF/IL-1, mRNA abundance of GTPCH and PTPS was increased approximately 64-fold and 10-fold, respectively. CONCLUSIONS The present study demonstrates for the first time the cytokine-dependent regulation of PTPS, the second enzyme in BH4 synthesis. Although GTPCH is believed to be the rate-limiting step, control of endothelial PTPS expression by cytokines may play an important role in regulating BH4-dependent nitric oxide production in the vascular system.
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Affiliation(s)
- P Linscheid
- Medical Clinic B Research Unit, Department of Medicine, University Hospital of Zurich, Switzerland
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Birnbacher R, Scheibenreiter S, Blau N, Bieglmayer C, Frisch H, Waldhauser F. Hyperprolactinemia, a tool in treatment control of tetrahydrobiopterin deficiency: endocrine studies in an affected girl. Pediatr Res 1998; 43:472-7. [PMID: 9545000 DOI: 10.1203/00006450-199804000-00006] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Severe tetrahydrobiopterin (BH4) deficiency is a naturally occurring model of cerebral catecholamine and serotonin shortage. Examination of the stimulated release and physiologic secretion pattern of several hormones in affected individuals permits certain conclusions concerning the involvement of these neurotransmitters in hormone regulation. Treatment, moreover, permits the ranking of the quality of the therapeutic regimens in use according to the degree of hormonal alteration. The 24-h secretion pattern of prolactin, GH, cortisol, and melatonin and the stimulated release of prolactin, GH, TSH, and gonadotropins were studied in an affected girl. Severe hyperprolactinemia with disruption of the pulsatile and circadian secretion pattern was the prevailing feature. The GH physiologic secretion pattern was not affected, but its stimulation was impaired. Melatonin displayed a normal circadian secretion pattern; the rhythm, however, was advanced by several hours. Conventional treatment of BH4 deficiency, i.e. BH4, 5-hydroxytryptophan, and L-DOPA/carbidopa (the last named given in three doses per day), suppresses prolactin levels merely for a few hours. L-DOPA/carbidopa given at shorter intervals or, even better, as a slow release preparation, is more effective in suppressing prolactin levels. Our data indicate immense hyperprolactinemia but few other hormonal disturbances in severe BH4 deficiency. Prolactin secretion may serve as an extremely sensitive marker for the hypothalamic dopamine content under different therapeutic regimens. Treatment with an L-DOPA/carbidopa slow release preparation produces virtually normal prolactin levels.
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Affiliation(s)
- R Birnbacher
- Department of Pediatrics, University of Vienna, Austria
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14
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Werner ER, Wachter H, Werner-Felmayer G. Determination of tetrahydrobiopterin biosynthetic activities by high-performance liquid chromatography with fluorescence detection. Methods Enzymol 1997; 281:53-61. [PMID: 9250966 DOI: 10.1016/s0076-6879(97)81008-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- E R Werner
- Institut für Medizinische Chemie und Biochemie, Universität Innsbruck, Austria
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15
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Werner ER, Werner-Felmayer G, Wachter H. High-performance liquid chromatographic methods for the quantification of tetrahydrobiopterin biosynthetic enzymes. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1996; 684:51-8. [PMID: 8906465 DOI: 10.1016/0378-4347(95)00507-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Tetrahydrobiopterin is a cofactor in hydroxylation reactions, including phenylalanine 4-monooxygenase, tyrosine 3-monooxygenase, tryptophan 5-monooxygenase, alkyl glycol ether monooxygenase and nitric oxide synthase. Determination of its biosynthesis is carried out to diagnose inherited diseases leading to partial defects in tetrahydrobiopterin synthesis. In addition, tetrahydrobiopterin synthesis is induced by proinflammatory cytokines, and intracellular levels of tetrahydro-biopterin in many cases limit the activity of tetrahydrobiopterin-dependent reactions, such as nitric oxide synthase in intact cells. Biosynthesis of tetrahydrobiopterin from guanosine 5'-triphosphate (GTP) requires the action of three enzymes, GTP-cyclohydrolase I (E.C. 3.5.4.16), 6-pyruvoyl tetrahydropterin synthase (EC, 4.6.1.10) and sepiapterin reductase (E.C. 1.1.1.153). Methods for quantification of biopterin and related pteridines in biological matrices by HPLC and application of these for determining the activity of the three tetrahydrobiopterin biosynthetic enzymes are reviewed in this article.
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Affiliation(s)
- E R Werner
- Institut für Medizinische Chemie and Piechemic, Universität Innsbuck, Austria
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Thöny B, Leimbacher W, Stuhlmann H, Heizmann CW, Blau N. Retrovirus-mediated gene transfer of 6-pyruvoyl-tetrahydropterin synthase corrects tetrahydrobiopterin deficiency in fibroblasts from hyperphenylalaninemic patients. Hum Gene Ther 1996; 7:1587-93. [PMID: 8864759 DOI: 10.1089/hum.1996.7.13-1587] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Tetrahydrobiopterin (BH4) deficiency, a variant form of hyperphenylalaninemia with progressive neurological dysfunction, is primarily caused by autosomal recessive mutations in the gene encoding the 6-pyruvoyl-tetrahydropterin synthase (PTPS). PTPS is a biosynthetic enzyme for the BH4 co-factor, and its deficiency is associated with a malfunction of the phenylalanine catabolism in the liver and a lack of biogenic amine neurotransmitters dopamine and serotonin in the brain. We have previously isolated the wild-type PTPS cDNA and identified several mutations responsible for a decreased enzyme in patients. This study reports the in vitro correction of BH4 deficiency by using retrovirus mediated transfer of the PTPS cDNA into primary fibroblast cultures established from different patients. The Bing packaging cell line was used for amphotropic virus production. Following PTPS gene transfer, stimulation with cytokines restored biosynthesis of BH4 in originally defective cells to values comparable to those of heterozygous fibroblasts from clinically healthy subjects. These results not only provide a direct proof that the mutations in PTPS were causative for the mutant phenotype, but they are also the first step toward gene therapy as a potential alternative approach to treat BH4 deficiency.
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Affiliation(s)
- B Thöny
- Department of Pediatrics, University of Zürich, Switzerland
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17
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Sakai T, Matsuishi T, Yamada S, Komori H, Iwashita H. Sulfamethoxazole-trimethoprim double-blind, placebo-controlled, crossover trial in Machado-Joseph disease: sulfamethoxazole-trimethoprim increases cerebrospinal fluid level of biopterin. J Neural Transm (Vienna) 1995; 102:159-72. [PMID: 8748680 DOI: 10.1007/bf01276511] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We performed a double-blind, placebo-controlled, crossover trial of sulfamethoxazole-trimethoprim (S-T) in 8 patients with Machado-Joseph disease (MJD), and measured the blood and cerebrospinal fluid levels of biopterins, biogenic amines or metabolites, and folate. The clinical results were as follows; mild improvements of hyperreflexia of knee jerks and of rigospasticity of the legs during S-T treatment period. In addition, S-T significantly reduced the times of 8 motor activities on the timed tests. The biochemical results showed that basal levels of all biopterins and homovanillic acid in the cerebrospinal fluid (CSF) were reduced to less than half the levels of those of controls with other neurological diseases. After S-T treatment, total and oxidized form of biopterins in the CSF increased significantly. Therefore, S-T may be effective to neurologic deficits through its mechanism of increasing the level of brain biopterins.
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Affiliation(s)
- T Sakai
- Department of Neurology, National Chikugo Hospital, Fukuoka, Japan
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18
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Blau N, Kierat L, Matasovic A, Leimbacher W, Heizmann CW, Guardamagna O, Ponzone A. Antenatal diagnosis of tetrahydrobiopterin deficiency by quantification of pterins in amniotic fluid and enzyme activity in fetal and extrafetal tissue. Clin Chim Acta 1994; 226:159-69. [PMID: 7923811 DOI: 10.1016/0009-8981(94)90213-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Prenatal diagnosis of tetrahydrobiopterin (BH4) deficiency was undertaken by evaluating the pterin patterns in amniotic fluid and the specific enzyme activities in fetal or extrafetal tissues. This allowed the prenatal diagnosis in 19 pregnancies at risk. In 8 families with a child already affected by dihydropteridine reductase deficiency 4 fetuses were diagnosed as homozygotes and 4 as heterozygotes for the defect. In 11 families with a child affected by 6-pyruvoyl tetrahydropterin synthase deficiency 4 fetuses were homozygous, 4 heterozygous and 3 normal. This study also advanced our knowledge of tetrahydrobiopterin metabolism during fetal development. The key enzymes involved in the biosynthesis of BH4 are expressed early and allow the fetus to be autotrophous for its cofactor requirement. In a twin pregnancy, both fetuses were diagnosed to be heterozygotes for dihydropteridine reductase deficiency and primapterin (7-biopterin) in amniotic fluid was increased. This indicates that pterin-4 alpha-carbinolamine dehydratase activity seems to be differently expressed during fetal life. As a consequence, pterins detected in amniotic fluid are of fetal origin and 6- and 7-substituted pterins can be present in amniotic fluid in higher proportions when compared with other body fluids.
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Affiliation(s)
- N Blau
- Division of Clinical Chemistry, University Children's Hospital, Zürich, Switzerland
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19
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Shintaku H, Hsiao KJ, Liu TT, Imamura T, Hase Y, Chen RG, Isshiki G, Oura T. Prenatal diagnosis of 6-pyruvoyl tetrahydropterin synthase deficiency in seven subjects. J Inherit Metab Dis 1994; 17:163-6. [PMID: 8051934 DOI: 10.1007/bf00735427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- H Shintaku
- Department of Pediatrics, Osaka City University Medical School, Japan
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20
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Ponzone A, Guardamagna O, Spada M, Ferraris S, Ponzone R, Kierat L, Blau N. Differential diagnosis of hyperphenylalaninaemia by a combined phenylalanine-tetrahydrobiopterin loading test. Eur J Pediatr 1993; 152:655-61. [PMID: 8404969 DOI: 10.1007/bf01955242] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We describe a new fully reliable method for the differential diagnosis of tetrahydrobiopterin-dependent hyperphenylalaninaemia (HPA). The method comprises the combined phenylalanine (Phe) plus tetrahydrobiopterin (BH4) oral loading test and enables the selective screening of BH4 deficiency when pterin analysis is not available or when a clear diagnosis has not been previously made. It should be performed together with the measurement of dihydropteridine reductase (DHPR) activity in blood. The new combined loading test was performed in nine patients with primary HPA, three with classical phenylketonuria (PKU), three with DHPR deficiency, and three with 6-pyruvoyl tetrahydropterin synthase (PTPS) deficiency. Three hours after oral Phe loading (100 mg/kg body weight), synthetic BH4 was administered orally at doses of either 7.5 or 20 mg/kg body weight. Amino acid (Phe and tyrosine) and pterin (neopterin and biopterin) metabolism and kinetics were analysed. By exploiting the decrease in serum Phe 4 and 8 h after administration, a clear response was obtained with the higher BH4 dose (20 mg/kg body weight), allowing detection of all cases of BH4 deficiency, as well as differentiation of BH4 synthesis from regeneration defects. Since DHPR deficient patients who were previously shown to be non-responsive to the simple BH4 loading test gave a positive response, the combined Phe plus BH4 loading test can be used as a more reliable tool for the differential diagnosis of HPA in these patients. Moreover, it takes advantage of being performed while patients are on a Phe-restricted diet.
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Affiliation(s)
- A Ponzone
- Department of Paediatrics, University of Sassari, Italy
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21
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Masada M. Enzymatic properties of 6-pyruvoyl tetrahydropterin synthase purified from fat bodies of silkworm larvae. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1993; 338:191-4. [PMID: 8304108 DOI: 10.1007/978-1-4615-2960-6_38] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- M Masada
- Department of Bioresources Chemistry, Faculty of Horticulture, Chiba University, Japan
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22
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Coskun T, Ozalp I, Tokatli A, Blau N, Niederwieser A. Hyperphenylalaninaemia due to tetrahydrobiopterin deficiency: a report of 16 cases. J Inherit Metab Dis 1993; 16:605-7. [PMID: 7609463 DOI: 10.1007/bf00711694] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- T Coskun
- Department of Pediatrics, Hacettepe University, Faculty of Medicine, Hacettepe/Ankara, Turkey
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23
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Hauer CR, Leimbacher W, Hunziker P, Neuheiser F, Blau N, Heizmann CW. 6-pyruvoyl tetrahydropterin synthase from salmon liver: amino acid sequence analysis by tandem mass spectrometry. Biochem Biophys Res Commun 1992; 182:953-9. [PMID: 1734893 DOI: 10.1016/0006-291x(92)91824-a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The most frequent variant of atypical phenylketonuria, an inborn error of metabolism, is characterized by a low activity of the 6-pyruvoyl tetrahydropterin synthase. We purified and characterized this enzyme from salmon liver known to contain high levels. After digestion, peptides were sequenced by tandem mass spectrometry and/or automated Edman microsequence analysis. Both a free amine terminus and an N-acetylated amine terminus were found, indicating the presence of two isoforms. The peptide sequences determined here have a high degree of homology with the protein sequence deduced from cDNA for rat 6-pyruvoyl tetrahydropterin synthase (1), however, the amine termini of these proteins differ significantly.
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Affiliation(s)
- C R Hauer
- Department of Pediatrics, University of Zurich, Switzerland
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24
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Guzman J, Schoedon G, Blau N. Production of monoclonal antibodies against human 6-pyruvoyl tetrahydropterin synthase and immunocytochemical localization of the enzyme. Biochem Biophys Res Commun 1992; 182:810-6. [PMID: 1734883 DOI: 10.1016/0006-291x(92)91804-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Monoclonal antibodies were produced against human pituitary gland 6-pyruvoyl tetrahydropterin synthase, one of the key enzymes in the biosynthesis of tetrahydrobiopterin, by in vitro immunization with the antigen directly blotted from SDS-PAGE to polyvinylidene difluoride membranes. The antibodies produced show crossreactivity in the enzyme linked immunosorbent assay, not only with the human 6-pyruvoyl tetrahydropterin synthase but some also with the same enzyme isolated from salmon liver. 6-Pyruvoyl tetrahydropterin synthase was localized immuno-enzymatically in peripheral blood smears and in skin fibroblasts by the use of these monoclonal antibodies and the alkaline phosphatase monoclonal anti-alkaline phosphatase labeling technique.
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Affiliation(s)
- J Guzman
- Department of Pediatrics, University of Zürich, Switzerland
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25
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Werner ER, Werner-Felmayer G, Fuchs D, Hausen A, Reibnegger G, Wels G, Yim JJ, Pfleiderer W, Wachter H. 6-Pyruvoyl tetrahydropterin synthase assay in extracts of cultured human cells using high-performance liquid chromatography with fluorescence detection of biopterin. JOURNAL OF CHROMATOGRAPHY 1991; 570:43-50. [PMID: 1797835 DOI: 10.1016/0378-4347(91)80199-m] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
An assay for 6-pyruvoyl tetrahydropterin synthase, the second enzyme in the conversion of guanosine triphosphate into tetrahydrobiopterin, has been developed. Cell extracts were incubated with enzymatically prepared dihydroneopterin triphosphate (80 microM) in the presence of Mg2+ (12 mM), excess sepiapterin reductase (EC 1.1.1.153) (2 nmol/min) and NADPH (2 mM). 6-Pyruvoyl tetrahydropterin, the product of the reaction, was thus converted into tetrahydrobiopterin. After oxidation of the reduced biopterin derivatives in acidic iodine solution, biopterin was enriched and separated from the abundant neopterin phosphates by solid-phase extraction on a strong cation exchanger. Biopterin was then directly eluted on a reversed-phase liquid chromatographic column and detected fluorimetrically using excitation at 353 nm and emission at 438 nm. The biopterin concentrations formed by the coupled enzyme reaction increased linearly with incubation times up to 90 min. The assay allows the quantification of 6-pyruvoyl tetrahydropterin synthase in cultured human cells.
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Affiliation(s)
- E R Werner
- Institute for Medical Chemistry and Biochemistry, University of Innsbruck, Austria
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26
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Allanson J, McInnes R, Bradley L, Tarby T, Naylor E, Nardella M. Combined transient and peripheral defects in tetrahydrobiopterin synthesis. J Pediatr 1991; 118:261-3. [PMID: 1993959 DOI: 10.1016/s0022-3476(05)80498-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- J Allanson
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Canada
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27
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Werner ER, Werner-Felmayer G, Fuchs D, Hausen A, Reibnegger G, Yim JJ, Pfleiderer W, Wachter H. Tetrahydrobiopterin biosynthetic activities in human macrophages, fibroblasts, THP-1, and T 24 cells. GTP-cyclohydrolase I is stimulated by interferon-gamma, and 6-pyruvoyl tetrahydropterin synthase and sepiapterin reductase are constitutively present. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39752-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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28
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Kerler F, Hültner L, Ziegler I, Katzenmaier G, Bacher A. Analysis of the tetrahydrobiopterin synthesizing system during maturation of murine reticulocytes. J Cell Physiol 1990; 142:268-71. [PMID: 2406277 DOI: 10.1002/jcp.1041420208] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The enzymes of tetrahydrobiopterin synthesis have been studied in murine bone marrow, in spleen, in erythrocytes, and in reticulocytes. Mice with chemically induced and with genetically conditioned reticulocytosis as found in the lactate dehydrogenase deficient strain (Ldh-1c/Ldh-1c) were used for analysis of reticulocytic enzyme activities. The activity of the biopterin synthesizing system is highest in bone marrow even though it amounts to only about 10% as compared with liver. The first enzyme of the biosynthetic pathway, GTP-cyclohydrolase, virtually disappears during the final maturation step of reticulocytes. In contrast, the activities of 6-pyruvoyltetrahydropterin synthase and of sepiapterin reductase of erythrocytes are only reduced to about one half of the reticulocyte level. The absence of biopterin in erythrocytes is therefore caused by the loss of the enzyme that initiates the pterin biosynthetic pathway.
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Affiliation(s)
- F Kerler
- GSF-Institut für Experimentelle Hämatologie, München, Federal Republic of Germany
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29
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Ponzone A, Blau N, Guardamagna O, Ferrero GB, Dianzani I, Endres W. Progression of 6-pyruvoyl-tetrahydropterin synthase deficiency from a peripheral into a central phenotype. J Inherit Metab Dis 1990; 13:298-300. [PMID: 1700190 DOI: 10.1007/bf01799379] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- A Ponzone
- Department of Paediatrics, University of Turin, Torino, Italy
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30
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Kerler F, Schwarzkopf B, Katzenmaier G, Le Van Q, Schmid C, Ziegler I, Bacher A. Biosynthesis of tetrahydrobiopterin: a sensitive assay of 6-pyruvoyltetrahydropterin synthase using [2'-3H]dihydroneopterin 3'-triphosphate as substrate. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 990:15-7. [PMID: 2492436 DOI: 10.1016/s0304-4165(89)80005-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Pyruvoyltetrahydropterin synthase catalyzes the release of tritiated water from [2'-3H]dihydroneopterin 3'-triphosphate. The tritiated water formed during the enzymatic reaction is separated from substrate by adsorption of the latter to activated charcoal. The sensitivity and specificity of the assay allows the determination of the enzyme in crude cell extract.
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Affiliation(s)
- F Kerler
- Gesellschaft für Strahlen- und Umweltforschung, Institut für Experimentelle Hämatologie, München, F.R.G
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31
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Niederwieser A, Shintaku H, Leimbacher W, Curtius HC, Hyànek J, Zeman J, Endres W. "Peripheral" tetrahydrobiopterin deficiency with hyperphenylalaninaemia due to incomplete 6-pyruvoyl tetrahydropterin synthase deficiency or heterozygosity. Eur J Pediatr 1987; 146:228-32. [PMID: 3297709 DOI: 10.1007/bf00716465] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Four patients in three families with "peripheral" tetrahydrobiopterin deficiency were investigated. They were characterized biochemically by a tetrahydrobiopterin-responsive hyperphenylalaninaemia, a high neopterin/biopterin ratio in urine and plasma, and normal or elevated concentrations of biopterin, homovanillic acid, and 5-hydroxyindole acetic acid in cerebrospinal fluid. From measurements of the activity of erythrocyte 6-pyruvoyl tetrahydropterin synthase (PTS, formerly called phosphate-eliminating enzyme) and phenylalanine loading tests in the patients and their parents, one patient was demonstrated to be heterozygous for PTS deficiency. The others were obviously genetic compounds (allelism) with incomplete PTS deficiency. Three of the children developed normally, two of them under treatment with tetrahydrobiopterin. In the latter two patients, significantly lower concentrations of biopterin, homovanillic acid, and 5-hydroxyindole acetic acid in cerebrospinal fluid were noted at age 7 months (when treatment was interrupted) than those observed at 3 and 5 weeks, respectively. The infant who is heterozygous for PTS deficiency was born small for gestational age and showed a moderately delayed psychomotor development. It is concluded that "peripheral" tetrahydrobiopterin deficiency is caused by a partial PTS deficiency with sufficient activity to cover the tetrahydrobiopterin requirement of tyrosine 3-hydroxylase and trytophan 5-hydroxylase in brain but not enough for phenylalanine 4-hydroxylase in liver. For therapy, tetrahydrobiopterin, 2-5 mg/kg in a single oral dose per day, is recommended to keep plasma phenylalanine normal. A careful observation of the mental development is indicated.
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