Methylmalonic Acidemia (Cobalamin Conditions)



Methylmalonic acidemia (MMA) is an inherited condition in which the body is unable to break down certain fats and proteins, which can lead to a harmful amount of organic acids and toxins in the body. MMA caused by cobalamin A or cobalamin B deficiencies is one type of methylmalonic acidemia. Babies with this form of the condition have trouble producing cobalamin enzymes A and B. Cobalamin enzymes are necessary for the body to break down certain foods.  The signs of methylmalonic acidemia cobalamin A and B disorders (Cbl A, B) can begin at any time from birth to adulthood. In most cases, signs first appear as early as the first few days after birth and can include sleeping longer or more often, vomiting, weak muscle tone (hypotonia), fever, breathing trouble, increased number of illnesses and infections, and increased bleeding and bruising. Many of these signs may occur when a baby eats foods the body cannot break down. Symptoms can be triggered by long periods of time without eating, illnesses, and infections.

Condition Type:

Methylmalonic acidemia (MMA) is estimated to affect 1 out of every 50,000 to 100,000 babies born in the United States. MMA caused by cobalamin disorders A and B (Cbl A, B) is only one form of methylmalonic acidemia. It is currently unknown the exact number of individuals affected by this specific form.

More Information for Parents:
Also known as:
  • Cbl A,B
  • Methylmalonic aciduria
  • CblA or cblB type
  • Adenosylcobalamin deficiency
  • Cobalamin A,B

Core Conditions