[(1)H] magnetic resonance spectroscopy of urine: diagnosis of a guanidinoacetate methyl transferase deficiency case.
For the first time, the use of urine [(1)H] magnetic resonance spectroscopy has allowed the detection of 1 case of guanidinoacetate methyl transferase in a database sample of 1500 pediatric patients with a diagnosis of central nervous system impairment of unknown origin. The urine [(1)H] magnetic resonance spectroscopy of a 9-year-old child, having severe epilepsy and nonprogressive mental and motor retardation with no apparent cause, revealed a possible guanidinoacetic acid increase. The definitive assignment of guanidinoacetic acid was checked by addition of pure substance to the urine sample and by measuring [(1)H]-[(1)H] correlation spectroscopy. Diagnosis of guanidinoacetate methyl transferase deficiency was further confirmed by liquid chromatography-mass spectrometry, brain [(1)H] magnetic resonance spectroscopy, and mutational analysis of the guanidinoacetate methyl transferase gene. The replacement therapy was promptly started and, after 1 year, the child was seizure free. We conclude that for this case, urine [(1)H] magnetic resonance spectroscopy screening was able to diagnose guanidinoacetate methyl transferase deficiency.
Tassini
Maria
M
The NMR Center University of Siena, Siena, Italy. tassini@unisi.it
Zannolli
Raffaella
R
Buoni
Sabrina
S
Engelke
Udo
U
Vivi
Antonio
A
Valensin
Gianni
G
Salomons
Gajja S
GS
De Nicola
Anna
A
Strambi
Mirella
M
Monti
Lucia
L
Morava
Eva
E
Wevers
Ron A
RA
Hayek
Joseph
J
D001921:Brain / Q000378:metabolism; D002648:Child; D002853:Chromatography, Liquid; D004252:DNA Mutational Analysis; D003677:Deficiency Diseases / Q000175:diagnosis* / Q000628:therapy / Q000652:urine*; D003937:Diagnosis, Differential; D004827:Epilepsy / Q000175:diagnosis / Q000628:therapy / Q000652:urine; D050937:Guanidinoacetate N-Methyltransferase / Q000172:deficiency* / Q000235:genetics / Q000627:therapeutic use; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis / Q000628:therapy / Q000652:urine; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D013058:Mass Spectrometry; D009069:Movement Disorders / Q000175:diagnosis / Q000628:therapy / Q000652:urine; D011522:Protons; D012640:Seizures / Q000175:diagnosis / Q000628:therapy / Q000652:urine; D016896:Treatment Outcome
D011522:Protons; D050937:Guanidinoacetate N-Methyltransferase