Glycine

Glycine is an amino acid found in protein-containing foods and produced by your body. This urine test measures 24-hour glycine excretion and is used in genetic metabolic screening. Abnormal glycine levels can indicate several inherited disorders, including primary hyperoxaluria, glycine encephalopathy, or other amino acid metabolism disorders. These conditions can cause kidney stones, neurological problems, or developmental delays if undiagnosed. Testing is often part of newborn screening or evaluation of children with unexplained developmental delay, kidney disease, or seizures.