A review of biochemical and molecular genetic aspects of tyrosine hydroxylase deficiency including a novel mutation (291delC)

• Published in: Journal of inherited metabolic disease 1999-06, Vol.22 (4), p.364-373
• Main Authors: Wevers, R. A., Rijk‐van Andel, J. F., Bräutigam, C., Geurtz, B., Heuvel, L. P. W. J., Steenbergen‐Spanjers, G. C. H., Smeitink, J. A. M., Hoffmann, G. F., Gabreëls, F. J. M.
• Format: Article
• Language: English
• Subjects: 3-Methoxy-4-hydroxyphenylethyleneglycol; 5-Hydroxyindoleacetic acid; Amino Acid Metabolism, Inborn Errors - enzymology; Amino Acid Metabolism, Inborn Errors - genetics; Amino Acid Metabolism, Inborn Errors - therapy; Aminoacid disorders; Biological and medical sciences; Errors of metabolism; homovanillic acid; Humans; Medical sciences; Metabolic diseases; Mutation; pterin; Tyrosine 3-Monooxygenase - deficiency; Tyrosine 3-Monooxygenase - genetics
• ISSN: 0141-8955; 1573-2665
• DOI: 10.1023/A:1005539803576

An overview is given of the current knowledge on the human tyrosine hydroxylase gene and on the biochemical aspects of diagnosing defects in this gene. Diagnostic biochemical findings are described in four cases of genetically confirmed tyrosine hydroxylase deficiency. Decreased CSF levels of homovanillic acid (HVA) and 3‐methoxy‐4‐hydroxyphenylethyleneglycol (MHPG), together with normal pterin and CSF tyrosine and 5‐hydroxyindoleacetic acid (5‐HIAA) concentrations are the diagnostic hallmarks of tyrosine hydroxylase deficiency. At the metabolite level the diagnosis can only be made reliably in CSF. Strict adherence to a standardized lumbar puncture protocol and adequate reference values are essential for diagnosis of this “new” treatable neurometabolic disorder. Measurements of HVA, vanillylmandelic acid (VMA) or catecholamines in urine are not relevant for diagnosing tyrosine hydroxylase deficiency. The diagnosis should be considered in all children with unexplained hypokinesia and other extrapyramidal symptoms. Three of our patients are homozygous for a mutation in exon 6 (698G>A) of the tyrosine hydroxylase gene and one patient was compound heterozygous for the same mutation and a novel truncating mutation in exon 3 (291delC).