Thiopurine methyltransferase (TPMT) is an enzyme that breaks down a class of drugs called thiopurines. TPMT tests are used to identify people at risk of developing severe side effects from thiopurine treatment.
Mercury is an element found in small quantities throughout the environment that can be toxic in various forms. Mercury testing is used to detect an excess amount of mercury in your blood and/or urine sample.
The MTHFR mutation test may sometimes be ordered when a person has elevated homocysteine levels, especially when the person has a personal or family history of premature cardiovascular disease or thrombosis.
Histamine is released from activated mast cells, often in an allergic response. Histamine tests measure it in blood or urine to confirm that a person has had an anaphylactic reaction or to help diagnose mastocytosis.