226 Newborn screening for six lysosomal diseases: Pilot study in Brazil Francyne Kubaski a , Inês Sousa b , Tatiana Amorim b , Danilo Pereira c , Joe Trometer d , Alexandre Souza e , Enzo Ranieri f , Giulia Polo g , Xinying Hong h , Xinying Hong h , Michael H. Gelb h , Roberto Giugliani a , a UFRGS/ HCPA/Inagemp, Porto Alegre, Brazil, b APAE, Salvador, Brazil, c Waters Technology, São Paulo, Brazil, d Perkin Elmer, Waltahm, MA, United States, e Perkin Elmer, São Paulo, Brazil, f Women's and Children's Hospital, Adelaide, Australia, g University Hospital of Padova, Padova, Italy, h University of Washington, Seattle, WA, United States Several lysosomal diseases (LDs) already have specific therapies that, especially when introduced early, provide better outcomes. This study aims to evaluate the feasibility of newborn screening (NBS) for selected LDs in Brazil, using tandem mass spectrometry (MS/MS). The study includes the screening of Gaucher, Fabry, Pompe, Krabbe, Niemann-Pick A/B, and Mucopolysaccharidosis (MPS) I. This is a prospective study in 20,000 unselected newborns from the state of Bahia, Brazil. The newborns with low enzyme activity will be further evaluated by biochemical and molecular genetics methods until the diagnostic status is clarified and they are referred for the appropriate management when indicated. The activity of the six lysosomal enzymes was analyzed with NeoLSD MS/MS kit (Perkin Elmer) on a Waters Xevo TQ-S Micro. Validation of the method was conducted in dried blood spots provided by the supplier and from newborns with these conditions. Instrument optimization was conducted to increase the signal and to decrease the in-source fragmentation. Initial cutoffs were established as a percentage of the median in nmoL/h/mL, as b0.97 (Gaucher), 1.17 (Fabry), 2.00 (Pompe), 0.29 (MPS I), 0.25 (Krabbe) and 0.60 (Niemann-Pick A/B). In a first run of 4734 newborn samples, the number of samples with activities below the cutoff in the first assay was: 14 (Gaucher), 22 (Fabry), 0 (Pompe), 16 (MPS I), 15 (Krabbe) and 8 (Niemann-Pick A/B). Nine of these samples had values below the cutoff for more than one enzyme, suggesting a pre-analytical problem. All samples below the cutoff are being retested and if they continue to show enzyme activities below the cutoff, specific biomarker analyses and molecular genotyping will be performed. The validation of the MS/MS method enabled the beginning of a pilot study in 20,000 samples, which will provide important information about the feasibility of an NBS for LDs in Brazil. doi:10.1016/j.ymgme.2019.11.235 227 Home infusion therapy with agalsidase alfa for patients with Fabry disease in Germany and Austria Anja Lachmann a , Christine Kurschat b , Almut Fritsch c , Florian Lagler d , Gere Sunder-Plassmann e , Peter Martus f , Martina Kralewski a , Julia B. Hennermann g , a Shire, a Takeda company, Berlin, Germany, b Department II of Internal Medicine and Center for Rare Diseases Cologne, University Hospital of Cologne, Cologne, Germany, c Universitätsklinikum Jena, Center for Rare Diseases, Jena, Germany, d Institute for Inherited Metabolic Diseases and Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria, e Division of Nephrol- ogy and Dialysis, Department of Medicine III, Medical University Vienna, Vienna, Austria, f Universitätsklinikum Tübingen, Institute for Clinical Epidemiology and Applied Biometry, Tübingen, Germany, g Villa Metabolica, Department of Pediatric and Adolescent Medicine, Univer- sity Medical Center Mainz, Mainz, Germany Enzyme replacement therapy (ERT) is a causal treatment for Fabry disease (FD). Because ERT is required lifelong, home therapy might improve patients' satisfaction with ERT and preserve quality of life (QOL). This observational study's objective was to demonstrate that a home treatment regimen with agalsidase alfa improves patients' satisfaction and maintains QOL in patients with FD. Patients received agalsidase alfa intravenously once every 2 weeks (q2w) under physician supervision at German and Austrian outpatient study centers. Eligible patients (age ≥ 4 years) were switched to home-based infusion after ≥6 weeks of infusions in the clinic. Home- based infusions were administered q2w by a specialized home infusion nurse. Data were collected at baseline, 6 and 12 months, and every 12 months thereafter, or at therapy discontinuation. Patients' satisfaction and QOL were measured by self-assessment question- naire (11-point Likert scale) and validated SF-36 questionnaire (mental component score [MCS] and physical component score [PCS]), respectively, after 12 months of home therapy. Safety was assessed by adverse events and infusion-related reactions. Of 114 patients with baseline documentation, 43.9% (n = 50) were male, and the mean ± SD age was 41.85 ± 16.02 years. Mean ± SD patients' satisfaction at 12 months increased 1.29 ± 2.46 points from baseline; however, the primary endpoint was not met as satisfaction was already high at baseline (P = .108). In a post-hoc analysis, 60% (21/35) of patients' satisfaction was higher with home-based infusion than with in-clinic infusions (P b .0001). Mean ± SD MCS and PCS scores increased 0.31 ± 8.09 and 0.05 ± 6.34 from baseline, respectively (P N .5 for both). Thus, increased patients' satisfaction and preservation of QOL was observed with ERT on home-based infusion. Whereas infusion-related reactions occurred in 15.8% (20/ 127), the safety profile under home-based infusion was no different from that of agalsidase alfa administered in the clinical setting. Any interventions due to AEs were timely and of equal quality as compared with the clinical setting. doi:10.1016/j.ymgme.2019.11.236 228 Longitudinal change in the urinary biomarkers of young pediatric patients with pathogenic variants in the GLA gene: Data from the MOPPet study Dawn A. Laney a , Myrl Holida b , Morgan F. Simmons a , Keirsa Nimmons a , Andrea M. Atherton c , Elizabeth Vengoechea d , Eric W. Hall a , Christy F. Kidwell e , Dawn Peck f , Linda Manwaring g , Tomi Toler g , Dorothy K. Grange g , Bruce Heese h , Christiane Auray-Blais i , a Emory University, Decatur, GA, United States, b University of Iowa, Iowa City, IA, United States, c Horizon Therapeutics, Lake Forest, IL, United States, d Sanofi Genzyme, Boston, MA, United States, e University of Missouri - Columbia, Columbia, MO, United States, f Mayo Clinic College of Medicine, Rochester, MN, United States, g Washington University, St. Louis, MO, United States, h Children's Mercy, Kansas City, MO, United States, i Université de Sherbrooke, Sherbrooke, QC, Canada The initiation of Fabry disease (FD) newborn screening in several states has resulted in an increased need for stronger data on symptoms and future disease progression in children between birth and age four years. In order to meet this need and determine the feasibility of collecting useful phenotypic data and biomarkers in Abstracts / Molecular Genetics and Metabolism 129 (2019) S16–S167 S94