Incomplete pediatric reference intervals for the management of patients with inborn errors of metabolism

OBJECTIVES: To evaluate the status of pediatric reference intervals for several biomarkers of inborn errors of metabolism (IEM). INTRODUCTION: There are several biomarkers that are used in many laboratories that specialize in biochemical genetics. Among them, there are acylcarnitines, total carnitine, amino acids, essential fatty acids, phytanic acid and very long chain fatty acids. These tests are key to exclusion or inclusion of an IEM, therefore appropriate age-related references intervals are crucial. A detailed review of each selected analyte is given. RESULTS: Published reference intervals do not always address the dependency of age, gender, or ethnic background; they are not established for newer laboratory methodologies and are derived from a limited number of healthy controls for most markers. CONCLUSIONS: To address the gap in pediatric reference intervals, the Canadian research project (CALIPER database) will establish comprehensive reference intervals for acylcarnitines, total carnitine, amino acids, essential fatty acids, phytanic acid, and very long chain fatty acids. All the tests will be limited to whole blood, plasma and serum samples.