Blood amino acids

Clinical Utility:

This tandem mass spectrometry (MSMS) semi-quantitative test is diagnostic for several aminoacidopathies. Disorders IDentified by MSMS

Specimen Types:

The most appropriate and convenient sample material is a dry blood spot. Blood can be obtained by a heel-prick from babies or finger-prick from older children and collected on Guthrie cards (provided by us). Blood collected in EDTA tube or heparin tube is acceptable from local hospitals. Plasma spots can also be used, but we do not encourage it.

Turn-around Time:

Routine: 2-3 days from receipt of sample

Stat: 24 hours from receipt of sample

Test Limitations & Interfering Substances:

The results of this test do not include values for all analytes due to lack of stable isotope internal standards for some compounds. Some of the metabolites have the same mass and this technique can not readily distinguish between them. These are leucine/isoleucine and glutamine/lysine. Furthermore, some of the metabolites degrade if dry blood spot is kept at room temperature for more than one week, particularly methionine. Therefore, we always recommend courier service rather than regular mail for this test.

Report Format:

The result is given in a one-page report that details the patient information, date of sample, date of analysis and a result code, which could be one of three:

"NOT REMARKABLE" "QUESTIONABLE" "ABNORMAL"

Interpretation of questionable or abnormal results will be provided. Recommendation for follow-up samples, or further tests, which are needed for confirmation, will be indicated.