This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Methionine adenosyltransferase deficiency is a very rare metabolic disorder resulting in an isolated increase of the amino acid methionine in the blood (hypermethioninemia). In most cases there are no symptoms and it is usually a benign condition, but some patients may present with neurologic or developmental problems and/or bad breath. It is caused by mutations in the MAT1A gene. Inheritance is autosomal recessive. When needed, treatment is with a diet restricting methionine. S-adenosylmethionine (SAMe) supplementation may also be useful.
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