Dietary practices in pyridoxine non-responsive homocystinuria: A European survey

S. Adam, M. F. Almeida, E. Carbasius Weber, H. Champion, H. Chan, A. Daly, M. Dixon, K. Dokoupil, D. Egli, S. Evans, F. Eyskens, A. Faria, C. Ferguson, P. Hallam, M. Heddrich-Ellerbrok, J. Jacobs, C. Jankowski, R. Lachmann, R. Lilje, R. LinkS. Lowry, K. Luyten, A. MacDonald*, C. Maritz, E. Martins, U. Meyer, E. Mueller, E. Murphy, L. V. Robertson, J. C. Rocha, I. Saruggia, P. Schick, J. Stafford, L. Stoelen, A. Terry, R. Thom, T. van den Hurk, M. van Rijn, A. van Teefelen-Heithoff, D. Webster, F. J. White, J. Wildgoose, H. Zweers

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

14 Citations (Scopus)


Background: Within Europe, the management of pyridoxine (B-6) non-responsive homocystinuria (HCU) may vary but there is limited knowledge about treatment practice.

Aim: A comparison of dietetic management practices of patients with B-6 non-responsive HCU in European centres.

Methods: A cross-sectional audit by questionnaire was completed by 29 inherited metabolic disorder (IMD) centres: (14 UK, 5 Germany, 3 Netherlands, 2 Switzerland, 2 Portugal, 1 France, 1 Norway, 1 Belgium).

Results: 181 patients (73% >16 years of age) with HCU were identified. The majority (66%; n= 119) were on dietary treatment (1-10 years, 90%; 11-16 years, 82%; and >16 years, 58%) with or without betaine and 34% (n = 62) were on betaine alone. The median natural protein intake (g/day) on diet only was, by age: 1-10 years, 12 g; 11-16 years, 11 g; and > 16 years, 45g. With diet and betaine, median natural protein intake (g/day) by age was: 1-10 years, 13 g; 11-16 years, 20g; and >16 years, 38g. Fifty-two percent (n = 15) of centres allocated natural protein by calculating methionine rather than a protein exchange system. A methionine-free L-amino acid supplement was prescribed for 86% of diet treated patients. Fifty-two percent of centres recommended cystine supplements for low plasma concentrations. Target treatment concentrations for homocystine/homocysteine (free/total) and frequency of biochemical monitoring varied.

Conclusion: In B-6 non-responsive HCU the prescription of dietary restriction by IMD centres declined with age, potentially associated with poor adherence in older patients. Inconsistencies in biochemical monitoring and treatment indicate the need for international consensus guidelines. (C) 2013 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)454-459
Number of pages6
JournalMolecular Genetics and Metabolism
Issue number4
Publication statusPublished - Dec-2013


  • Homocystinuria
  • Betaine
  • Homocysteine
  • Methionine
  • Protein restricted diet

Cite this