Detection in Newborn using Tandem Mass Spectrometry

The application of tandem mass spectrophotometry has been used in the research and development of newborn screening. It started in the early 1990’s and is still very much in use today. A tandem mass spectrophotometry- Tandem MS or MS/MS- is a type of mass spectrophotometry which is used to analyze the components of any type of substance especially biological substances.

 

In the case of screening for VLCAD in a newborn, the Tandem MS is used. The Tandem MS is made of two mass spectrometers that are joined by a chamber. The chamber will break the molecule to many different components that made the substance.

Schematic of Tandem Mass Spectroscopy

 

When a sample of the newborn’s blood is inserted, it is “sorted” and “weighed” by the mass spectrometer to get amino acids and acylcarnitines*. The acylcarnitines are identified by the size of the fatty acid that’s attached to the carnitine. After identifying and weighing the acylcarnitines, the mass spectrometer will produce results showing us how much of fatty acid is present. Depending on the amount of fatty acid present (eg; small, medium or long chain), the individual will then be diagnosed with the type of fatty acid oxidation disorder.

*acylcarnitine- a fatty acid attached to a carnitine (transportation system for fats) Acylcarnitine profile is a diagnostic test for inherited disorders of fatty acid and branched-chain amino acid catabolism. Patients with this type of metabolic disorder accumulate disease-specific acylcarnitines that correlate with the acyl co-enzyme.

Reference:

Unknown. (2011) Acylcarnitines: analysis in plasma and whole blood using tandem mass spectrometry.. Available at: http://www.ncbi.nlm.nih.gov/pubmed/21207283 [Accessed: 8th January 2013].

Unknown. (n.d.) A Layperson's guide to Tandem Mass Spectrometry and Newborn Screening. [e-book] Bridgeville, PA, USA: NeoGen Labs. p.1-3. http://masspec.scripps.edu/metabo_science/Tandem%20Mass%20Spectrometry%20Chace.pdf [Accessed: 8th January 2013].

Unknown. (2009) Lovely Baby. [image online] Available at: http://www.webmastergrade.com/top-15-cute-babies-wallpaper/ [Accessed: 10th January 2013]. 

Unknown. (n.d.) Schematic of Tandem Mass Spectroscopy. [image online] Available at: http://en.wikipedia.org/wiki/File:MS_MS.png [Accessed: 10th January 2013].