Multiplex enzyme assay using tandem mass spectrometry for newborn screening of lysosomal storage diseases

BIOL 177

Michael H. Gelb, gelb@chem.washington.edu1, Frantisek Turecek, turecek@chem.washington.edu2, C. Ronald Scott, crscott@u.washington.edu3, and Ding Wang2. (1) Departments of Chemistry and Biochemistry, University of Washington, Box 351700, Seattle, WA 98195, (2) Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA 98195-1700, (3) Department of Pediatrics, University of Washington School of Medicine, Box 356320, Seattle, WA 98195
Newborn screening of inborn errors of metabolism is carried out in cases where a treatment for the disease is available and in cases where early treatment leads to a better treatment outcome. The method of choice is now tandem mass spectrometry, which is currently being used to quantify the levels of amino acids and acyl carnitines in dried blood spots on newborn screening cards for the early detection of about two dozen metabolic diseases. In this method, an accumulated metabolite is detected as the signature for the enzyme deficiency disease. We are interested in developing assays for lysosomal storage diseases because of the recent development of treatments. Many lysosomal enzymes are active in re-hydrated dried blood spots, and we have been able to add a cassette of substrates to this sample for direct enzyme assay. The cassette of products that are formed are quantified by tandem mass spectrometry using internal standards for accurate quantification. A multiplex assay has been developed for six lysosomal storage diseases, Fabry, Gaucher, Hurler, Krabbe, Niemann-Pick-A/B, and Pompe. This multiplex assay is being transitioned into newborn screening labs. A pilot study has been initiated in New York State.
 

Uncovering the Metabolome and Metabolic Defects
9:00 AM-12:00 PM, Wednesday, 13 September 2006 Moscone Center -- Room 238, Oral

Division of Biological Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006