Hypermethioninemia

תיאור

Hypermethioninemia is an excess of a particular protein building block (amino acid), called methionine, in the blood. This condition can occur when methionine is not broken down (metabolized) properly in the body.

People with hypermethioninemia often do not show any symptoms. Some individuals with hypermethioninemia exhibit intellectual disability and other neurological problems; delays in motor skills such as standing or walking; sluggishness; muscle weakness; liver problems; unusual facial features; and their breath, sweat, or urine may have a smell resembling boiled cabbage.

Hypermethioninemia can occur with other metabolic disorders, such as homocystinuria, tyrosinemia, and galactosemia, which also involve the faulty breakdown of particular molecules. It can also result from liver disease or excessive dietary intake of methionine from consuming large amounts of protein or a methionine-enriched infant formula. The condition is called primary hypermethioninemia when it is not associated with other metabolic disorders or excess methionine in the diet.

Inheritance patterns

The source lists the following possible inheritance patterns: Autosomal dominant; Autosomal recessive. More than one pattern can apply in different cases.

Related genes

• MAT1A

• AHCY

• GNMT

Other names

Deficiency of methionine adenosyltransferase

Glycine N-methyltransferase deficiency

GNMT deficiency

Hepatic methionine adenosyltransferase deficiency

MAT deficiency

MET

Methionine adenosyltransferase deficiency

Methioninemia

S-adenosylhomocysteine hydrolase deficiency