Deficiency of guanidinoacetate methyltransferase results in a low creatine and creatinine formation. Diagnosis of this deficiency can reliably be made by quantification of the precursor of creatine, guanidinoacetic acid, in urine, plasma and cerebrospinal fluid.
- guanidino-[13C2]acetic acid
Synthesis and application
EA Struys, EEW Jansen, HJ ten Brink, NM Verhoeven, MS van der Knaap, C Jakobs. An accurate stable isotope dilution gas chromatographic - mass spectrometric approach to the diagnosis of guanidinoacetate methyltransferase deficiency. J Pharm Biomed Anal 18 (1998) 659-665.