Evaluation of two year treatment outcome and limited impact of arginine restriction in a patient with GAMT deficiency.
A 4-year-old female with history of developmental regression and autistic features was diagnosed with guanidinoacetate methyltransferase deficiency at age 21 months. Upon treatment, she showed improvements in her developmental milestones, sensorial-neural hearing loss and brain atrophy on cranial-MRI. The creatine/choline ratio increased 82% in basal ganglia and 88% in white matter on cranial MR-spectroscopy. The CSF guanidinoacetate decreased 80% after six months of ornithine and creatine supplementation and an additional 8% after 18 months of additional arginine restricted diet. We report the most favorable clinical and biochemical outcome on treatment in our patient.
Division of Biochemical Diseases, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada. smahmutoglu@cw.bc.ca
Saadet
S
Mercimek-Mahmutoglu
Mary
M
Dunbar
Andrea
A
Friesen
Susan
S
Garret
Carol
C
Hartnett
Linda
L
Huh
Graham
G
Sinclair
Sylvia
S
Stockler
Stephen
S
Wellington
Petra J W
PJ
Pouwels
Gajja S
GS
Salomons
Cornelis
C
Jakobs
D001120:Arginine / Q000172:deficiency*; D002675:Child, Preschool; D004032:Diet; D005260:Female; D005998:Glycine / Q000031:analogs & derivatives / Q000097:blood / Q000134:cerebrospinal fluid / Q000652:urine; D050937:Guanidinoacetate N-Methyltransferase / Q000172:deficiency* / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008661:Metabolism, Inborn Errors / Q000178:diet therapy* / Q000201:enzymology*; D016896:Treatment Outcome
D001120:Arginine; C494506:GAMT protein, human; D050937:Guanidinoacetate N-Methyltransferase; C004946:glycocyamine; D005998:Glycine