Prostate Specific Antigen (PSA) is produced exclusively by cells of the prostate gland. Used in conjunction with the digital rectal examination, PSA is a useful screening test for benign prostate enlargement, prostatitis and prostate cancer development.

The Rheumatoid Arthritis Factor is often evaluated in patients suspected of having any form of arthritis or destructive articular disease even though positive results can be due to other causes, and negative results do not rule out disease. But, in combination with signs and symptoms, it can play a role in both diagnosis and disease prognosis. It is part of the usual disease criteria of rheumatoid arthritis.

Quest Diagnostics test code 17911 is for a DNA mutation analysis of Methylenetetrahydrofolate Reductase (MTHFR). The test determines if a patient has one, two, or no copies of either of the two mutations in the MTHFR gene, C677T and A1298C.

Changes in the methylenetetrahydrofolate reductase gene can lead to certain health conditions. One of them is hyperhomocysteinemia (high blood levels of homocysteine), which is a risk factor for cerebrovascular disease, cerebral vein thrombosis, coronary artery disease, myocardial infarction, and venous thrombosis. At least 40 mutations in the MTHFR gene have been identified in people with homocystinuria, a disorder in which the body is unable to process certain amino acids properly.