Lysosomal and Peroxisomal Storage Disorders Screen, Blood Spot
Method Description Describes how the test is performed and provides a method-specific reference
This assay measures the activity of enzymes associated with 6 lysosomal storage disorders as well as C20, C22, C24, and C26 lysophosphatidylcholine (LPC) species in dried blood spots (DBS) by tandem mass spectrometry. The 6 enzymes are deficient or absent in Gaucher, Niemann-Pick type A and type B, Pompe, Krabbe, or Fabry disease, or mucopolysaccharidosis I. Long chain (C24 and C26) LPC species are elevated in patients with peroxisomal disorders such as X-linked adrenoleukodystrophy and peroxisomal biogenesis disorders.
Three 1/8" DBS are excised from a single specimen and placed into individual microtiter plates. One spot is treated with a cocktail containing acid sphingomyelinase-specific substrate and internal standard. To the second DBS a cocktail containing substrate and internal standard for beta-glucocerebrosidase, alpha-glucosidase, alpha-galactosidase, galactocerebrosidase, and alpha-L-iduronidase is added. The 2 enzyme plates are sealed and incubated for 19 hours. The third DBS is extracted with methanol containing d4-C26 LPC. The extract is then evaporated under heated nitrogen, reconstituted and stored refrigerated until day 2 of the procedure. Following the 19-hour incubation, the enzyme plates are combined and then purified by liquid-liquid extraction and solid-phase extraction. The purified extracts are evaporated, reconstituted in the prepared LPC plate, and analyzed by tandem mass spectrometry.(Unpublished Mayo method)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Tuesday; 8 a.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test