Hypermethioninemia due to glycine N-methyltransferase deficiency is a rare inherited disorder caused by a deficiency of the enzyme glycine N-methyltransferase (GNMT). This enzyme is responsible for the metabolism of the amino acid glycine. When GNMT is deficient, glycine accumulates in the body, leading to an increase in the amino acid methionine. This can cause a variety of symptoms, including mental retardation, seizures, and liver dysfunction. Treatment typically involves dietary management and supplementation with vitamins and minerals.

Symptoms of Hypermethioninemia due to glycine N-methyltransferase deficiency can include:

-Developmental delay
-Intellectual disability
-Seizures
-Movement disorders
-Growth retardation
-Feeding difficulties
-Liver dysfunction
-Hypoglycemia
-Hyperammonemia
-Hypoproteinemia
-Hyperbilirubinemia
-Hyperuricemia
-Hypertriglyceridemia
-Hypercholesterolemia
-Hypocalcemia
-Hypophosphatemia
-Hypokalemia
-Hypomagnesemia
-Hypothyroidism
-Hypogonadism
-Hypocalciuria
-Hyperammonemic encephalopathy

1. Inherited genetic mutation: The most common cause of hypermethioninemia due to glycine N-methyltransferase deficiency is an inherited genetic mutation in the GNMT gene. This gene provides instructions for making an enzyme called glycine N-methyltransferase, which is involved in the metabolism of the amino acid methionine.

2. Environmental factors: Exposure to certain environmental toxins, such as lead, mercury, and arsenic, can also cause hypermethioninemia due to glycine N-methyltransferase deficiency.

3. Medications: Certain medications, such as anticonvulsants, can also cause hypermethioninemia due to glycine N-methyltransferase deficiency.

1. Dietary management: A low-protein diet is recommended to reduce the amount of methionine in the diet.

2. Vitamin B12 supplementation: Vitamin B12 is important for the metabolism of methionine and can help reduce levels of methionine in the blood.

3. Medications: Medications such as betaine, folinic acid, and choline can help reduce levels of methionine in the blood.

4. Liver transplant: In some cases, a liver transplant may be necessary to treat hypermethioninemia due to glycine N-methyltransferase deficiency.

1. Family history of Hypermethioninemia due to glycine N-methyltransferase deficiency
2. Genetic mutations in the GNMT gene
3. Exposure to certain environmental toxins
4. Certain medications
5. Liver disease
6. Malnutrition
7. Alcoholism
8. Advanced age

At this time, there is no cure for hypermethioninemia due to glycine N-methyltransferase deficiency. However, there are medications that can help manage the symptoms. These include medications to reduce elevated levels of methionine, such as betaine, and medications to reduce elevated levels of homocysteine, such as folate, vitamin B6, and vitamin B12. Additionally, dietary modifications may be recommended to reduce the amount of methionine in the diet.