Propionic acidemia is a condition that occurs when your body lacks an enzyme called propionyl-CoA carboxylase. This enzyme is important for processing certain parts of proteins and fats in the right way. Without it, harmful substances can build up in the body, causing problems in the blood, urine, and tissues that can be harmful.
The symptoms of propionic acidemia usually start in the first few days after a baby is born. At first, the baby might have trouble feeding, feel tired, have weak muscles, and throw up. If not treated, these symptoms can get worse and lead to serious issues like organ damage, seizures, coma, and even death. Propionic acidemia might also be linked to problems like developmental issues, trouble learning, frequent infections, and heart problems. The seriousness of these symptoms can vary, but if someone has symptoms from infancy and doesn’t get treatment, they usually don’t live past the first year. In some cases, the signs of propionic acidemia can show up later in childhood or even in adulthood. For these individuals, symptoms might be triggered by things like not eating for a while, having a fever, or getting sick. Right now, there’s no cure for propionic acidemia. The main focus of treatment is managing the diet to make sure the person gets the right nutrition. In some cases, a liver transplant might be helpful.
Propionic acidemia is caused by pathogenic (disease-causing) variants in either the PCCA or PCCB genes and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. Of the known cases of propionic acidemia, approximately 35-50% have been attributed to mutations in PCCA, while 50-65% have been attributed to PCCB.
Other names for this condition are hyperglycinemia with ketoacidosis and leukopenia, ketotic hyperglycinemia, PCC deficiency, propionicacidemia, and propionyl-CoA carboxylase deficiency.