Newborn screening is intended to identify inborn error of metabolism thereby making early therapeutic interventions and decreasing likelihood of mortality or lifelong disability. Tandem mass spectrometry (MS/MS) detects abnormal levels of amino acids, free carnitine and acylcarnitines indicating defects of amino acid metabolism such as phenylketonuria(PKU) and maple syrup urine disease (MSUD), defects of organic acid oxidation metabolism and fatty acid oxidation metabolic disorders on account of enzyme deficiency in biochemical pathways.
Jasem’s newborn screening of amino acids and acylcarnitines extracted from a single of a dried-blood spot (DBS), with stable-isotope-labeled internal standards and without derivatization, can be performed with 3.5 min of instrument time.
Alanine, Arginine, Aspartic acid, Citrulline, Gutamic acid, Glycine, Leucine,Methionine, Ornithine, Phenylalanine, Proline, Tyrosine, Valine, Free carnitine,C2 Acetyl carnitine, C3 Propionyl carnitine, C4 Butyryl carnitine, C5 Isovaleryl carnitine, C8 Octanoyl carnitine, C14 Myristoyl carnitine, C16 Palmitoyl carnitine.
Precursor ion scanning: Detection of characteristic mass fragments (85 m/z) for Carnitine/Acylcarnitine.
Neutral Loss: Identification of 46 m/z mass fragments for amino acids.
MRM: Determination of all spesific mass fragments for Amino acids and Carnitine/Acylcarnitine
Punch 3.0 mm of specimen from DBS
Add 100 µl of IS mixture for extraction and shake gently 15 minutes
Transfer the supernatant to a vial and inject to LC-MS/MS system