quantification in a plasma sample of betaine, an amino acid derived from glycine. Betaine has been identified as a potential biomarker for coronary artery disease. The trait is plasma betaine measurement (EFO_0007787, an Experimental Factor Ontology entry). Also known as: plasma N,N,N-Trimethylglycine measurement, plasma glycine betaine measurement, plasma trimethylaminoacetate measurement, plasma trimethylammonioacetate measurement.