Vitamin B12-unresponsive methylmalonic acidemia (MMA) is a rare inherited metabolic disorder caused by a deficiency of the enzyme methylmalonyl-CoA mutase. This enzyme is responsible for breaking down certain proteins and fats in the body. Without it, the body cannot properly process these proteins and fats, leading to a buildup of methylmalonic acid in the blood. Symptoms of MMA include poor growth, developmental delays, seizures, and intellectual disability. Treatment typically involves a combination of dietary changes, vitamin B12 supplementation, and medications.

The symptoms of Vitamin B12-unresponsive methylmalonic acidemia can vary depending on the severity of the condition, but may include:

-Developmental delay

-Failure to thrive

-Weakness

-Muscle wasting

-Lethargy

-Irritability

-Vomiting

-Diarrhea

-Seizures

-Liver and kidney dysfunction

-Abnormal heart rhythms

-Vision and hearing loss

-Growth retardation

-Abnormal facial features

-Abnormal blood clotting

-Anemia

-Hyperammonemia

-Metabolic acidosis

The most common cause of Vitamin B12-unresponsive methylmalonic acidemia is a mutation in the MMAA gene, which is responsible for the production of the enzyme methylmalonyl-CoA mutase. Other causes include mutations in the MMADHC gene, which is responsible for the production of the enzyme methylmalonyl-CoA dehydrogenase, and mutations in the MUT gene, which is responsible for the production of the enzyme methylmalonyl-CoA epimerase.

1. Dietary management: A low-protein diet supplemented with essential amino acids and fatty acids is recommended.

2. Vitamin B12 supplementation: Vitamin B12 injections are recommended to maintain adequate levels of the vitamin in the body.

3. Medication: Medications such as cobalamin analogues, betaine, and folinic acid may be prescribed to help reduce methylmalonic acid levels.

4. Surgery: Surgery may be recommended to remove the affected organ or tissue.

5. Gene therapy: Gene therapy may be used to replace the defective gene responsible for the condition.

6. Stem cell transplantation: Stem cell transplantation may be used to replace the defective cells with healthy ones.

1. Genetic mutations in the MMACHC gene
2. Mutations in the MUT gene
3. Mutations in the CUBN gene
4. Mutations in the MMAA gene
5. Mutations in the MMAB gene
6. Mutations in the MMADHC gene
7. Mutations in the MMADH gene
8. Mutations in the MCEE gene
9. Mutations in the MUTYH gene
10. Mutations in the SUCLA2 gene
11. Mutations in the SUCLG1 gene
12. Mutations in the SUCLG2 gene
13. Mutations in the SUCLG3 gene
14. Mutations in the SUCLG4 gene
15. Mutations in the SUCLG5 gene
16. Mutations in the

There is no cure for Vitamin B12-unresponsive methylmalonic acidemia, but there are medications that can help manage the symptoms. These medications include carnitine, biotin, and hydroxycobalamin. Additionally, dietary modifications, such as avoiding certain foods that are high in protein, can help reduce the symptoms.