Lessons from 30 years of selective screening for tetrahydrobiopterin deficiency.
J Inherit Metab Dis
; 33(Suppl 2): S219-23, 2010 Oct.
Article
em En
| MEDLINE
| ID: mdl-20458544
ABSTRACT
In addition to being hyperphenylalaninemic, patients lacking tetrahydrobiopterin (BH4) are deficient in the neurotransmitters whose synthesis depends on the normal activity of tetrahydrobiopterin-dependent tyrosine and tryptophan hydroxylases. Consequently, these patients have to be rapidly recognized among hyperphenylalaninemic babies, since they need specific and early substitutive therapy. Since 1980, BH4 metabolism has been investigated in 2,186 hyperphenylalaninemic babies, using HPLC measurement of pteridines in urine to recognize tetrahydrobiopterin synthesis deficiency (GTP cyclohydrolase and PTPS deficiency) and direct DHPR assay in dried blood samples to recognize DHPR deficiency. A total of 73 tetrahydrobiopterin deficient patients have been detected. Considering the group of neonates born in France (1,342), out of the 32 BH4 deficient patients which have been detected, only 8 were from caucasian families. The lessons from that experience are (1) tests on blood and urine collected on filter paper cards commend itself by their convenience and simplicity, and samples can be collected on the first visit of the screened infants to the out-patient clinic; and (2) the preconceaved idea that newborns with moderate elevation of blood phenylalanine are false positives of the screening or mild forms of hyperphenylalaninemia explains that a significant number of cases were investigated after 1 month of age; however, in half of BH4-deficient babies, blood phenylalanine was below 10 mg/dl (0.6 mmol/l).
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Biopterinas
/
Triagem Neonatal
/
Erros Inatos do Metabolismo
Tipo de estudo:
Diagnostic_studies
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Prognostic_studies
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Screening_studies
Limite:
Humans
/
Newborn
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article