## Oral Presentations  
O-01. High Resolution Accurate Mass Spectrometry Enables Simultaneous Analysis of Amino Acids, Acylcarnitines and Organic Acids from Dried Blood Spots  
[PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] Newborn Screening, Department of Pediatrics and Adolescent Medicine, Medical University of Vienna  
Introduction: Determination of organic acids (OA) from plasma and urine is a common method for confirmation or differential diagnosis for children found positive for various inborn errors of metabolism in newborn screening. Mass spectrometers as typically used for newborn screening are not capable of OA analysis directly from dried blood spots (DBS). The aim of this study was to set up a method, which is suitable to simultaneously measure amino acids, acyl carnitines, as well as OA, and to evaluate its applicability for screening for organic acidemias and disorders of fatty acid oxidation. Method: Using a heated electrospray ionization high resolution mass spectrometer a quantitative screening panel was created, which in addition to the established amino acid and acyl carnitine profile includes 28 OA. Amino acid and acylcarnitines could be measured with satisfying intra- and inter-day variance in 578 samples of healthy newborns and proved to be satisfactory for our screening laboratory. DBS from 41 affected children (12 propionic acidemia, four methylmalonic acidemia, eight Very Long- und eight Medium-Chain Acyl-CoA Dehydrogenase-Deficient (VLCADD and MCADD), 11 Long-Chain 3-Hydroxy Acyl-CoA Dehydrogenase-Deficient (LCHADD), and six Glutaric acidemia type I (GA I)) were compared to DBS from healthy newborns. Result: We could show that the additional measurement of propionylglycine und methylmalonic acid is suitable to confirm elevated propionylcarnitine results in the same sample. Additionally, it was possible to distinguish between propionic acidemia and methylmalonic acidemia. We observed several OA concentrations in DBS from patients affected with VLCADD, MCADD and LCHADD to significantly differ to those from healthy controls. Furthermore, the ratio of 3-OH-glutaric acid to glutaconic acid was highly significantly altered in DBS from GA1 patients compared to healthy controls. Conclusions: We showed that it is possible to determine OA from the first DBS within a normal newborn screening routine. This could lead to a reduction of false positive findings, in particular for the relatively unreliable propionylcarnitine. This method could also provide a direct differential diagnosis between propionic acidemia and methylmalonic academia. _O-02. Newborn Screening for Sickle Cell Disease by FIA-MS/MS_  
[PERSON] 1, [PERSON] 1, [PERSON] 2, [PERSON] 1 and [PERSON] 3  
1 Newborn Screening Laboratory, Charite--Universitatsmedizin Berlin, Berlin, Germany  
2 Labor Berlin GmbH, FB Labormedizin, Berlin, Germany  
3 Department of Pediatric Oncology/Hematology/BMT, Charite--Universitatsmedizin Berlin, Berlin, Germany  
Sickle cell disease (SCD) is an inborn error of hemoglobin synthesis characterized by the formation of the Hb variant S (HbS) instead of normal Hb (HbA). Production of HbS in combination with a lack of HbA is, therefore, pathognomonic for SCD. Techniques to detect Hb variants, such as HPLC, isoelectric focusing, or capillary electrophoresis, are well established, and are adapted to the needs of a neonatal screening lab. However, the implementation of these methods into existing programs requires additional technical equipment and expertise. Moreover, chromatograms or spherograms have to be manually revised by a technician, and heterozygous states and clinically silent variants are detected and reported by the instrument. Tandem mass spectrometry with flow injection (FIA-MS/MS) is a fast and specific method being used for screening of inherited metabolic diseases for about 20 years. Recently, the application of MS/MS for SCD screening with automated analysis and reporting has been presented, excluding the detection of heterozygous states ([PERSON] 2014).