Glycine N-methyltransferase Deficiency


Glycine N-methyltransferase deficiency (GNMT deficiency) is caused by mutation in the GNMT gene (606628). Glycine N-methyltransferase catalyzes the synthesis of N-methylglycine (sarcosine) from glycine using S-adenosylmethionine (AdoMet) as the methyl donor. GNMT acts as an enzyme to regulate the ratio of S-adenosylmethionine to S-adenosylhomocysteine (AdoHcy) and participates in the detoxification pathway in liver cells. A defect in this enzyme causes accumulation of methionine in the plasma and transaminases in the serum. Symptoms include hepatomegaly.

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References

  1. Uniprot: Q14749
  2. OMIM: Entry 606664
  3. Engelke, U., van der Graaf, M., Heerschap, A., Hoenderop, S., Moolenaar, S., Morava, E., Wevers, R. (2007). Handbook of 1H-NMR spectroscopy in inborn errors of metabolism: body fluid NMR spectroscopy and in vivo MR spectroscopy (pp 51) (2nd ed). Heilbronn: SPS Verlagsgesellschaft
  4. Luka Z, Cerone R, Phillips JA 3rd, Mudd HS, Wagner C: Mutations in human glycine N-methyltransferase give insights into its role in methionine metabolism. Hum Genet. 2002 Jan;110(1):68-74. Epub 2001 Dec 7. Pubmed
  5. Mudd SH, Cerone R, Schiaffino MC, Fantasia AR, Minniti G, Caruso U, Lorini R, Watkins D, Matiaszuk N, Rosenblatt DS, Schwahn B, Rozen R, LeGros L, Kotb M, Capdevila A, Luka Z, Finkelstein JD, Tangerman A, Stabler SP, Allen RH, Wagner C: Glycine N-methyltransferase deficiency: a novel inborn error causing persistent isolated hypermethioninaemia. J Inherit Metab Dis. 2001 Aug;24(4):448-64. Pubmed