Clinical Use: Clinicians use the CSF:Plasma Glycine Ratio to diagnose glycine encephalopathy (non – ketotic hyperglycinemia).
Background: Glycine is one of the non-essential amino acids and is used to help create muscle tissue and convert glucose into energy. It is also essential to maintaining healthy central nervous and digestive systems. Glycine is used in the body to help construct normal DNA and RNA strands – the genetic material needed for proper cellular function and formation. Without glycine the body would not be able to repair damaged tissues; the skin would become slack as it succumbed to UV rays, oxidation, and free radical damage, and wounds would never heal.

Glycine is considered a glucogenic amino acid, which means it helps supply the body with glucose needed for energy. It helps regulate blood sugar levels, and thus glycine supplementation may be useful for treating symptoms characterized by low energy and fatigue, such as hypoglycemia, anaemia, and Chronic Fatigue Syndrome (CFS). Glycine encephalopathy (non – ketotic hyperglycinemia), is a rare autosomal recessive inherited metabolic disorder. This disorder is characterized by abnormally high levels of the amino acid glycine in bodily fluids and tissues.

One role of glycine is to act as a neurotransmitter, which is a chemical messenger that transmits signals in the brain. Glycine encephalopathy is caused by a defect in the glycine cleavage system (GCS), an enzyme complex that normally breaks down glycine in the body. A defect in the GCS enzyme complex causes excess glycine to build up in bodily fluids, tissues, and organs, in particular the brain and cerebrospinal fluid (CSF). Excess glycine in the brain and CSF results in serious medical problems, including encephalopathy, hence the name of the disorder.

Reference Ranges: Glycine (Plasma): 102 – 395 umol/L
Glycine (CSF): 3.2 – 16.3 umol/L
CSF:Plasma/Glycine Ratio: 0.01 – 0.04
Associated Diseases:
Patient Preparation:
Specimen Requirements: CSF: Collected into a plain universal.
Plasma: Lithium Heparin
Turnaround Time: 4 weeks
Additional Information:
Referred Test: Referred test
Location: Paediatric Metabolic Centre