What Is Propionic Acidemia (PA)?

PA is an inherited condition caused by a faulty gene.

Children with PA can't break down some types of fat and certain amino acids. Amino acids are the building blocks of protein, present in many foods.

As a result, substances called organic acids build up in the blood and urine.

This causes children to have lethargy, "floppy" muscles, poor appetite, and vomiting.

The Center for Rare Disease Therapy at UPMC Children's Hospital of Pittsburgh has experts in PA.

How Common Is Propionic Acidemia?

PA is a recessive genetic disorder that occurs when a child inherits the faulty gene from both parents.

It affects about:

PA is more common in places with a higher marriage rate between blood relatives.

It may affect as many as:

  • 1 in 1,000 Greenland Inuits.
  • 1 in 5,000 people in certain tribes in Saudi Arabia.

Propionic Acidemia Causes

Changes in two genes — PCCA and PCCB — cause PA.

These genes tell your body how to make an enzyme that helps break down proteins. Without this enzyme, a toxic substance builds up in the body and causes health problems.

Parents can carry a gene for PA without having the disease.

If both parents carry the faulty gene, there's a:

  • 25% chance their child will have PA.
  • 50% chance their child will be a carrier.
  • 25% chance their child will be neither a carrier nor have PA.

The risk of PA between males and females is the same.

Propionic Acidemia Symptoms in Children

Children with PA usually form symptoms within a few days after birth.

These include:

  • Poor feeding and failure to thrive. Babies with PA often don't want to eat and hence, don't grow as they should.
  • Low energy, seeming listless.
  • Low muscle tone, with muscles feeling floppy.
  • Vomiting, which can lead to dehydration.
  • Seizures (about 30% of infants with PA have seizures).

Without treatment, symptoms can worsen and cause:

  • Brain damage.
  • Intellectual disabilities.
  • Vision problems.
  • Pancreatitis (inflammation of the pancreas).
  • Kidney problems.
  • Heart failure.
  • Bleeding problems and increased stroke risk.

More rarely, infants with PA don't have symptoms early in life. This is late-onset propionic academia.

The symptoms come on later in childhood and often involve a child having a developmental delay.

Diagnosing Propionic Acidemia

Many states like Pennsylvania include PA in the standard newborn screening test.

Measuring levels of certain substances in the blood helps doctors diagnose PA at birth.

Doctors can diagnose it before birth with prenatal screening tests for those at high risk.

If either screening misses PA, doctors often diagnose it in the first weeks of life. They can diagnose it through use of a blood test and a family history.

They may also do genetic testing to confirm a broken gene.

Propionic Acidemia Treatment Options

There's no cure for PA, but we work closely with you and your loved ones to help manage it.

Babies and children with PA:

  • May need fluid therapy to make sure they don't get dehydrated.
  • Will work with a nutritionist to follow a special, low-protein diet.
  • May need other supplements and fluids to make sure they get the nutrients they need.
  • May need medicine to prevent infections.

Some children need hemodialysis. This treatment involves an artificial kidney machine that removes waste products from the blood.

We also find these supportive techniques can help children with PA:

  • Physical therapy. This can help improve muscle tone and mobility.
  • Speech therapy. This can help children with speech delays or swallowing problems.
  • Occupational therapy. This can help children with developmental delays, feeding issues, low vision, and other PA symptoms function better at home.
  • Special education programs. This can provide children who may have intellectual disabilities with the resources they need as they learn and grow.

Liver transplants can help children with severe PA and other metabolic diseases.

Your doctor will talk to your family about whether this is an option.

Jerry Vockley, MD, PhD

Chief of Medical Genetics and Genomics

Dr. Vockley is a global leader in the field of inborn errors of metabolism and genetic and genomic medicine.

He's also a founder of the North American Metabolic Academy.

Your Child's PA Consult and Care: What to Expect

If a doctor diagnosed your child with propionic acidemia, we want you to know you're not alone. The Center for Rare Disease Therapy is here to help. 

Here's what you can expect when you come to us for your child's PA consult and care. 

What should I expect at my child's first visit for PA?

Your child's first visit will take four to six hours.

Your child will have a complete assessment.

The doctor will make or confirm a PA diagnosis and determine how much the disease has progressed.

Because we work as a team here at the center, other experts might see your child during your visit.

These may include experts in:

  • Immune system diseases.
  • Blood diseases.
  • Bone marrow or liver transplants.
  • Genetic counseling.
  • Child development.

What happens after my child visits the Center for Rare Disease Therapy?

Members of your child's PA care team will talk with you about the next steps, such as:

  • Options for treating propionic acidemia.
  • Ways to improve your child's quality of life at home.

If surgery might be a treatment option for your child's PA, we'll discuss all the details. We'll let you know how you and your child can prepare.

By the end of your visit, you'll have a care plan tailored to your child's PA disease and health needs. We'll also schedule a follow-up visit in three months.

You'll meet our nurse practitioner. Before your next appointment, you can contact them by phone or video conference if you have any questions or concerns.

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

How long will I wait for my child's PA test results?

We will call within two weeks to discuss the test results and the next steps for your child's PA care.

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

MyCHP is free to patients, parents, and guardians of UPMC Children's Hospital of Pittsburgh.

Partners in Your Child's PA Care

When a child has a rare disease like propionic acidemia, it affects the whole family.

At the Center for Rare Disease Therapy, every child we see receives a tailored treatment plan and family-centered care.

We also look at each family member as our partner. We know the best care happens when we merge our PA expertise with your knowledge of your child and their needs. 

Center for Rare Disease Therapy patient stories

Meet Our Patients

Learn how we give children with PA and their loved ones hope.

Read stories from our Center for Rare Disease Therapy patients. »

Contact Us

At the Center for Rare Disease Therapy, every child diagnosed with a rare disease receives an individualized treatment plan and family-centered care.

For an appointment, consultation, or patient referral with an expert at UPMC Children’s Hospital of Pittsburgh, please fill out our contact form and we will be in touch within two business days.

Phone: 412-692-7273
Email: RareCare@chp.edu