Glycine Quantitative Plasma Test

The Glycine Quantitative Plasma test measures the amount of glycine in your plasma.

This test is done to:

• Diagnose metabolic disorders or inborn errors of metabolism.
• Monitor glycine levels during treatment for these disorders.
• Assess a patient's response to therapy.
• Identify glycine deficiency that can cause various neurological symptoms.

Your doctor may recommend this test:

• If you have symptoms of metabolic disorders such as seizures, developmental delay, lethargy, or respiratory problems.
• If you have a family history of metabolic disorders.
• When you are undergoing therapy for metabolic disorders.

Elevated or low levels may indicate underlying metabolic disorders such as non-ketotic hyperglycinemia or hyperammonemia.

During this test, a small sample of your blood will be collected from a vein in your arm. You might feel a slight pinch or prick during sample collection. 

You may need to fast for 4–6 hours before the test, based on your doctor’s suggestions. Inform them about any medications or supplements you are taking which may interfere with the test results. It is advisable to consult your healthcare provider to determine if there are any particular requirements you should be aware of.

Other tests that may be ordered alongside the Glycine Quantitative Plasma test include:

• Urine Organic Acid Test: This test helps diagnose metabolic disorders and inborn errors of metabolism.
• Amino Acid Profile: This test provides information on levels of various amino acids in the blood, which helps diagnose other metabolic disorders.

Quantitative plasma amino acid analysis 

Non-ketotic hyperglycinemia is a rare genetic metabolic disorder that prevents the breakdown of glycine in the body. It causes an accumulation of glycine in the brain, leading to seizures, developmental delay, and other neurological symptoms. This condition can be diagnosed through the Glycine Quantitative Plasma test.