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February 5, 2026 / Blogs

Rare Disease Spotlight: Propionic Acidemia

Rare Disease Spotlight: Propionic Acidemia

When a newborn struggles to feed, becomes unusually drowsy, or develops unexplained vomiting in their first days of life, parents may face an unexpected diagnosis: propionic acidemia. This rare metabolic disorder affects approximately 1 in 100,000 people in the United States3, yet for the families living with it, the challenges are anything but uncommon.

Propionic acidemia (PA) is a rare inherited metabolic disorder that affects the body’s ability to properly process certain parts of proteins and fats. ¹ It is classified as an organic acidemia, a condition where a specific enzymatic deficiency leads to a harmful buildup of acids in the blood and urine. ² Like many other metabolic disorders, PA is a lifelong condition that requires careful management to prevent serious health complications. ¹

The genetic basis of propionic acidemia

PA is caused by mutations in either the PCCA or PCCB genes. These genes provide the instructions for making two parts of an enzyme called propionyl-CoA carboxylase.2

This enzyme plays a vital role in breaking down specific amino acids, the building blocks of proteins, as well as certain lipids and cholesterol. 2 When this enzyme is defective or missing, these substances cannot be processed correctly.1 This leads to an accumulation of propionic acid and other toxic compounds in the body, which can damage organs like the brain and heart.

PA follows an autosomal recessive inheritance pattern; this means a child must inherit two copies of the non-working gene, one from each parent, to develop the disorder.1 Parents who carry only one copy of the mutated gene typically do not show symptoms themselves. When both parents are carriers, there is a 25% chance with each pregnancy that their child will be born with PA.2

Symptoms and diagnosis

The symptoms of propionic acidemia can vary in severity and age of onset. In most cases, symptoms appear within the first few days of life.1

Infants with the acute neonatal form may experience:

  • Poor feeding and lack of appetite
  • Vomiting
  • Excessive lethargy or drowsiness
  • Weak muscle tone (hypotonia)

If left untreated, these early symptoms can quickly progress to more serious medical issues, including seizures, coma, and potential heart or brain damage due to the buildup of toxic substances.

In some individuals, the condition presents later in childhood or even adulthood. This less severe, late-onset form may appear with milder symptoms such as developmental delays, chronic vomiting, or movement disorders.2

PA is often identified through newborn screening programs, which test for elevated levels of specific markers in a baby's blood shortly after birth. Diagnosis is then confirmed through further genetic testing or biochemical analysis of blood and urine.1

Treating propionic acidemia

While there is no cure for PA, early diagnosis and strict management can improve outcomes.1 The primary goal of treatment is to control the buildup of toxic acids while ensuring the body gets enough nutrition for growth.2

Management strategies typically include:

  • Dietary management: individuals must follow a strictly protein-restricted diet to limit the intake of isoleucine, valine, methionine, and threonine, the amino acids the body cannot process.1
  • Medical foods: specialized formulas that are free of the offending amino acids are essential to provide protein and other nutrients necessary for health.1
  • Medication: supplements such as L-carnitine may be prescribed to help remove toxic compounds from the body.2
  • Regular monitoring: frequent blood tests are required to monitor acid levels and nutritional status.3

In some severe cases, a liver transplant may be considered. Since the liver produces the enzyme that is missing in people with PA, a transplant can provide a new source of the enzyme, though it is a major surgical procedure with its own risks.1

How ZOIA Pharma can help

Living with PA means navigating complex dietary restrictions, specialized formulas, and constant monitoring, but families don't have to manage this journey alone.

Managing PA is a lifelong journey, but patients don't have to walk it alone. To learn more about managing metabolic disorders such as PA, visit ZOIA Pharma.


  1. Propionic Acidemia – National Organization for Rare Disorders.
    https://rarediseases.org/rare-diseases/propionic-acidemia/. Accessed 17 Dec. 2025.
  2. Galarreta Aima, Carolina I., et al. ‘Propionic Acidemia’. GeneReviews®, edited by Margaret P. Adam et al., University of Washington, Seattle, 1993. PubMed,
    http://www.ncbi.nlm.nih.gov/books/NBK92946/.
  3. Propionic Acidemia: MedlinePlus Genetics. https://medlineplus.gov/genetics/condition/propionic-acidemia/. Accessed 17 Dec. 2025.