Current Practices and Challenges in the Diagnosis and Management of PKU in Latin America: A Multicenter Survey

Abstract

This study aimed to describe the current practices in the diagnosis and dietary management of phenylketonuria (PKU) in Latin America, as well as the main barriers to treatment. We developed a 44-item online survey aimed at health professionals. After a pilot test, the final version was sent to 25 practitioners working with inborn errors of metabolism (IEM) in 14 countries. Our results include 22 centers in 13 countries. Most countries (12/13) screened newborns for PKU. Phenylalanine (Phe) targets at different ages were very heterogeneous among centers, with greater consistency at the 0-1 year age group (14/22 sought 120-240 µmol/L) and the lowest at >12 years (10 targets reported). Most countries had only unflavored powdered amino acid substitutes (10/13) and did not have low-protein foods (8/13). Only 3/13 countries had regional databases of the Phe content of foods, and only 4/22 centers had nutrient analysis software. The perceived obstacles to treatment were: low purchasing power (62%), limited/insufficient availability of low-protein foods (60%), poor adherence, and lack of technical resources to manage the diet (50% each). We observed a heterogeneous scenario in the dietary management of PKU, and most countries experienced a lack of dietary resources for both patients and health professionals.

Keywords: PKU; low-protein diet; newborn screening; phenylketonuria.

Figure 1

Frequencies of blood phenylalanine (Phe, a) and tyrosine (Tyr, b) monitoring for each age group as adopted by the Latin American centers included in the study (n = 22). Numbers within columns represent relative percentages.

Figure 2

Target Phe levels during treatment in different age groups, as adopted by the studied centers (n = 22). Phe: phenylalanine.

Figure 3

Total protein (natural + protein substitute) prescriptions, in different age groups, in the studied centers (n = 22) Some centers did not fully answer this question; therefore, the sample size varies in different age groups.

Figure 4

Barriers to treatment most commonly perceived by the respondents (n = 22). Values represent the median scores assigned by the respondents. * Educational level of patients and caregivers; ** Technical resources required or desirable to manage the diet, such as a local database of the Phe content of foods and specialized nutrition software.