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JIMD Rep. 2017;32:87-94. doi: 10.1007/8904_2016_556. Epub 2016 Jun 21.

Newborn Screening for Vitamin B.

JIMD reports

Jürgen G Okun, Hongying Gan-Schreier, Tawfeq Ben-Omran, Kathrin V Schmidt, Junmin Fang-Hoffmann, Gwendolyn Gramer, Ghassan Abdoh, Noora Shahbeck, Hilal Al Rifai, Abdul Latif Al Khal, Gisela Haege, Chuan-Chi Chiang, David C Kasper, Bridget Wilcken, Peter Burgard, Georg F Hoffmann

Affiliations

  1. Department of General Pediatrics, Division of Inherited Metabolic Diseases, University Children's Hospital, Heidelberg, Germany. [email protected].
  2. Department of General Pediatrics, Division of Inherited Metabolic Diseases, University Children's Hospital, Heidelberg, Germany.
  3. Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar.
  4. Chinese Foundation of Health, Taipei City, Taiwan.
  5. Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria.
  6. NSW Newborn Screening Programme, The Children's Hospital at Westmead, Westmead, NSW, Australia.

PMID: 27325427 PMCID: PMC5362558 DOI: 10.1007/8904_2016_556

Abstract

BACKGROUND: In classical homocystinuria (HCU, MIM# 236200) due to the deficiency of cystathionine β-synthase (EC 4.2.1.22) there is a clear evidence for the success of early treatment. The aim of this study was to develop and evaluate a two-tier strategy for HCU newborn screening.

METHODS: We reevaluated data from our newborn screening programme for Qatar in a total number of 125,047 neonates including 30 confirmed HCU patients. Our hitherto existing screening strategy includes homocysteine (Hcy) measurements in every child, resulting in a unique dataset for evaluation of two-tier strategies. Reevaluation included methionine (Met) levels, Met to phenylalanine (Phe) ratio, and Hcy. Four HCU cases identified after database closure were also included in the evaluation. In addition, dried blood spot samples selected by Met values >P97 in the newborn screening programs in Austria, Australia, the Netherlands, and Taiwan were analyzed for Hcy.

RESULTS: Met to Phe ratio was found to be more effective for first sieve than Met, sorting out nearly 90% of normal samples. Only 10% of the samples would have to be processed by second-tier measurement of Hcy in dried blood spots. As no patient with HCU was found neither in the samples investigated for HCU, nor by clinical diagnosis in the other countries, the generalization of our two-tier strategy could only be tested indirectly.

CONCLUSION: The finally derived two-tier algorithm using Met to Phe ratio as first- and Hcy as second-tier requires 10% first-tier positives to be transferred to Hcy measurement, resulting in 100% sensitivity and specificity in HCU newborn screening.

Keywords: Classical homocystinuria; Cystathionine β-synthase; Dried blood spots; Homocysteine; Newborn screening; Two-tier strategy

References

  1. J Inherit Metab Dis. 2007 Aug;30(4):522-9 - PubMed
  2. JIMD Rep. 2012;5:1-6 - PubMed
  3. Clin Chem. 2010 Nov;56(11):1686-95 - PubMed
  4. N Engl J Med. 2003 Jun 5;348(23):2304-12 - PubMed
  5. J Inherit Metab Dis. 1998 Oct;21(7):738-47 - PubMed
  6. J Inherit Metab Dis. 2015 Nov;38(6):1007-19 - PubMed
  7. Clin Chem. 2000 Jan;46(1):122-3 - PubMed
  8. J Pediatr. 2010 Mar;156(3):427-32 - PubMed
  9. Pediatrics. 2006 May;117(5 Pt 2):S296-307 - PubMed
  10. Mol Genet Metab. 2010 Jan;99(1):1-3 - PubMed
  11. Hum Mutat. 2006 Jul;27(7):719 - PubMed
  12. Sports Med. 2000 Jul;30(1):1-15 - PubMed
  13. Paediatr Perinat Epidemiol. 2006 Sep;20(5):372-8 - PubMed
  14. Clin Chem. 2005 Jan;51(1):257-8 - PubMed
  15. Nature. 2014 Feb 13;506(7487):150-2 - PubMed
  16. Genet Med. 2016 Feb;18(2):162-7 - PubMed
  17. Genet Med. 2011 Mar;13(3):230-54 - PubMed
  18. Hum Mutat. 2009 Jun;30(6):1021-2 - PubMed
  19. Science. 1964 Mar 27;143(3613):1443-5 - PubMed
  20. Pediatr Res. 2003 Jun;53(6):1013-8 - PubMed
  21. Eur J Pediatr. 1998 Apr;157 Suppl 2:S84-7 - PubMed
  22. J Formos Med Assoc. 2006 Nov;105(11):882-6 - PubMed

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