Vitamin B12-responsive methylmalonic acidemia type cblB is a rare inherited disorder caused by a deficiency of the enzyme methylmalonyl-CoA mutase. This enzyme is necessary for the breakdown of certain proteins and fats. Without it, the body cannot properly process certain amino acids, leading to a buildup of methylmalonic acid in the blood. Symptoms of this disorder can 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-responsive methylmalonic acidemia type cblB vary depending on the severity of the condition, but may include:

- Poor feeding
- Vomiting
- Lethargy
- Weakness
- Developmental delay
- Seizures
- Irritability
- Poor growth
- Hypotonia
- Anemia
- Jaundice
- Abnormal movements
- Abnormal gait
- Abnormal reflexes
- Abnormal eye movements
- Abnormal heart rate
- Abnormal breathing
- Abnormal blood pressure
- Abnormal liver function tests
- Abnormal kidney function tests
- Abnormal electrolyte levels
- Abnormal blood sugar levels
- Abnormal cholesterol levels
- Abnormal white blood cell counts

Vitamin B12-responsive methylmalonic acidemia type cblB is caused by mutations in the MMACHC gene. This gene provides instructions for making an enzyme called methylmalonyl-CoA mutase. This enzyme is involved in the breakdown of certain proteins and fats. Mutations in the MMACHC gene reduce or eliminate the activity of this enzyme, leading to a buildup of methylmalonic acid in the body. This buildup can cause a variety of symptoms, including developmental delays, seizures, and vision problems.

1. Vitamin B12 supplementation: Vitamin B12 supplementation is the mainstay of treatment for cblB methylmalonic acidemia. Vitamin B12 is usually given as intramuscular injections, although oral supplementation is also possible.

2. Dietary modifications: Dietary modifications may be necessary to reduce the amount of methylmalonic acid in the body. This may include avoiding certain foods that are high in methylmalonic acid, such as dairy products, eggs, and certain meats.

3. Folic acid supplementation: Folic acid supplementation may be necessary to reduce the amount of methylmalonic acid in the body.

4. Enzyme replacement therapy: Enzyme replacement therapy may be necessary to replace the missing enzyme in cblB methylmalonic acidemia. This therapy is usually given as an intravenous infusion.

5. Other

1. Mutations in the MMACHC gene
2. Inheritance of two mutated copies of the MMACHC gene from both parents
3. Deficiency of dietary vitamin B12
4. Impaired absorption of vitamin B12
5. Certain medications that interfere with vitamin B12 absorption
6. Certain medical conditions that interfere with vitamin B12 absorption, such as Crohn’s disease, celiac disease, and gastric bypass surgery
7. Certain genetic disorders, such as homocystinuria and transcobalamin II deficiency

Yes, there is a cure for Vitamin B12-responsive methylmalonic acidemia type cblB. Treatment typically involves a combination of dietary modifications, vitamin B12 supplementation, and medications such as betaine, folinic acid, and carnitine. Additionally, some patients may require a bone marrow transplant.