Reliability of enzyme assays in dried blood spots for diagnosis of 4 lysosomal storage disorders

Introduction: Lysosomal storage disorders (LSD) are inherited diseases caused, in the majority of them, by the deficiency of lysosomal enzymatic activities. Ob-jectives: We aimed to analyze the usefulness of DBS samples for diagnosis of 4 LSDs, with the availability of a large quantity of patient samples. Design and methods: Blood samples from previously diagnosed patients with Fabry, Gaucher, Hunter, and Maro-teaux-Lamy syndromes and normal control indi-viduals, were collected and dispen-sed in filter paper, and used for enzymatic activity determination. Re-sults: Diagnosis of hemi/homo-zygous patients with Fabry, Hunter and Maroteaux-Lamy diseases using DBS samples showed ideal parameters of 100% sen-sitivity and specificity. DBS assay for Gaucher dis-ease would need a posterior confirmatory step. Con-clusions: Leukocyte measu-rement is the only reli-able way to diagnose Gaucher disease. For Hunter, Fabry and Maroteaux-Lamy disorders discrimina-tion between patients and controls seems adequate by DBS.Laboratorio de Investigaciones del Sistema Inmun