How practical are recommendations for dietary control in phenylketonuria?

• Published in: The Lancet (British edition) 2002-07, Vol.360 (9326), p.55-57
• Main Authors: Walter, JH, White, FJ, Hall, SK, MacDonald, A, Rylance, G, Boneh, A, Francis, DE, Shortland, GJ, Schmidt, M, Vail, A
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aminoacid disorders; Biological and medical sciences; Blood; Child; Child, Preschool; Diet; Errors of metabolism; Humans; Infant; Medical disorders; Medical sciences; Metabolic diseases; Metabolic disorders; Metabolism; Multicenter Studies as Topic; Patient Compliance; Phenylalanine - blood; Phenylketonurias - diet therapy; Treatment Outcome
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(02)09334-0

In patients with phenylketonuria, blood phenylalanine concentration during childhood is the major determinant of cognitive outcome. Guidelines provide age-related recommendations for treatment. To ascertain the extent to which these aims are achievable, we audited results from four centres for the years 1994–2000. The median proportion of samples with phenylalanine concentrations above those recommended was less than 30% for those younger than age 10 years but almost 80% for those aged 15 years and older. Similarly, the median frequency of blood sampling, expressed as a proportion of that recommended, was more than 80% for patients younger than 10 years but less than 50% by age 15 years. Our results indicate the difficulty of maintaining control in phenylketonuria, especially in older rather than younger children.