What Is Methylmalonic Acidemia?

Inborn Error of Energy Metabolism

Methylmalonic acidemia (MMA) is a genetic condition caused by a faulty gene.

Children with MMA lack a protein that the body needs to break down fats and cholesterol inside cells. These substances build up in cells, causing damage to the brain, liver, kidneys, and other organs.

MMA symptoms may include:

  • Throwing up.
  • “Floppy” muscles.
  • Excessive fatigue.

Children with MMA do not gain weight and grow as expected to.

Jerry Vockley, MD, PhD

Chief of Genetic and Genomic Medicine

Dr. Vockley is a global leader in inborn errors of metabolism treatment and research. He’s also a founder of the North American Metabolic Academy.

Your Child's MMA Disease Consult and Care: What to Expect

If your child has MMA, we want you to know you're not alone. The Center for Rare Disease Therapy (CRDT) at UPMC Children's Hospital of Pittsburgh is here to help.

Here’s what you can expect when you come to us for your child’s MMA consult.

What should I expect at my child’s first visit for MMA care?

Your first visit to the CRDT should take about 4 to 6 hours. Your child will receive a thorough exam from one of the center's doctors.

The doctor will make or confirm a MMA diagnosis and find out how much it has progressed.

Because we work as a team at the center, other doctors and staff might see your child during your visit.

These may include a:

  • Brain, spine, and nervous system doctor.
  • Heart specialist.
  • Surgeon.
  • Nutritionist.
  • Genetic counselor.
  • Psychologist.
  • Child development specialist.

What are the next steps after my child's MMA visit to the Center for Rare Disease Therapy?

Members of your child's care team will talk with you about:

  • Likely next steps for your child.
  • MMA treatment options.
  • Ways to help your child's quality of life at home.

By the end of your visit, you'll have a MMA care plan tailored to your child's needs. We'll also schedule a follow-up visit.

You'll meet our nurse practitioner. You can contact them by phone or video conference with any concerns before your next visit.

Before you leave, please ask us about your child's MMA diagnosis, treatment, or anything else on your mind.

How long will I need to wait for my child's MMA test results?

We'll call within 2 weeks to review the test results and the next steps for your child's MMA care.

You can also find your child's test results by logging into MyCHP — Children's patient portal.

MyCHP lets you manage your child's health online. It's free for kids getting treatment at Children's and their loved ones.

Partners in Your Child's MMA Care

A child with a rare disease like MMA affects the whole family. We see each family member as our partner at the Center for Rare Disease Therapy.

The best care happens when we merge our MMA expertise with your knowledge of your child's needs.

Center for Rare Disease Therapy patient storiesMeet Our Rare Disease Center Patients

Learn how others are finding help and hope for their child’s rare disease through the expertise at UPMC Children’s.

View Center for Rare Disease Therapy patient stories »

Contact Us About Your Child’s MMA

At the CRDT, every child diagnosed with a rare disease receives a tailored treatment plan and family-centered care.

For an appointment, consult, or referral, contact us:

We’ll be in touch within 2 business days.