title: Gas chromatography/mass spectrometry-based urine metabolome study in children for inborn errors of metabolism: An Indian experience.
abstract: OBJECTIVE
  The present study highlights the feasibility of gas chromatography/mass spectrometry (GC/MS)-based analysis for simultaneous detection of >200 marker metabolites in urine found in characteristic pattern in inborn errors of metabolism (IEM) in India.
  
  
  METHODS
  During this retrospective study conducted from July 2013 to January 2016, we collected urine specimens on filter papers from Indian children across the country along with relevant demographic and clinical data. The laboratory technique involved urease pretreatment followed by deproteinization, derivatization, and subsequent computer-aided analysis of organic acids, amino acids, fatty acids, and sugars by GC/MS, which enable chemical diagnosis of IEM.
  
  
  RESULTS
  Totally 23,140 patients were investigated for IEM with an estimated frequency of about 1.40%, that is, 323 positive cases. Most frequent disorders observed were of primary lactic acidemia (27.2%) and organic acidemia (methylmalonic aciduria, glutaric acidemia type I, propionic aciduria, etc.) followed by aminoacidopathies (maple syrup urine disease, phenylketonuria, tyrosinemia, etc.). Furthermore, alkaptonuria, canavan disease, and 4-hydroxybutyric aciduria were also diagnosed. Prompt treatment following diagnosis led to a better outcome in a considerable number of patients.
  
  
  CONCLUSIONS
  GC/MS with one-step metabolomics enables quick detection, accurate identification, and precise quantification of a wide range of urinary markers that may not be discovered using existing newborn screening programs. The technique is effective as a second-tier test to other established screening technologies, as well as one-step primary screening tool for a wide spectrum of IEM.
authors: PreventiNe Life Care, Navi Mumbai, Maharashtra, India. Electronic address: mahesh.hampe@preventine.com.
authors: Mahesh H
authors: MH
authors: Hampe
authors: PreventiNe Life Care, Navi Mumbai, Maharashtra, India.
authors: Shrimant N
authors: SN
authors: Panaskar
authors: PreventiNe Life Care, Navi Mumbai, Maharashtra, India.
authors: Ashwini A
authors: AA
authors: Yadav
authors: PreventiNe Life Care, Navi Mumbai, Maharashtra, India.
authors: Pramod W
authors: PW
authors: Ingale
mesh_terms: D000465:Algorithms; D000596:Amino Acids / Q000032:analysis; D002648:Child; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007194:India; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008661:Metabolism, Inborn Errors / Q000201:enzymology / Q000378:metabolism*; D012189:Retrospective Studies; D050644:Succinate-Semialdehyde Dehydrogenase / Q000378:metabolism
chemical_list: D000596:Amino Acids; D050644:Succinate-Semialdehyde Dehydrogenase
keywords: Aminoacidopathies; Gas chromatography/mass spectrometry (GC/MS); Inborn errors of metabolism (IEM); Newborn screening; Organic acidemia