Propionic acidemia (PROP) is a rare genetic condition. PROP results from a mutation or error in a person’s DNA or genes. Due to this mistake, people with PROP have problems with breaking down certain fats properly. PROP occurs when the body does not make enough or makes non-working PROP enzyme, propionyl-CoA carboxylase (PCC). Enzymes are special proteins that help break down the food we eat into the pieces our body can use for energy. In this case, the job of the PCC enzyme is to break down the amino acids isoleucine, valine, methionine, and threonine and a type of fat called odd-chain fats. Those with PROP can’t use these materials for energy because they can't be broken down. This also causes a build-up of too many unused odd-chain fatty acids and amino acids, which can be harmful to the body.
Those affected by PROP can show symptoms usually within a few days after birth. Symptoms may include sleeping longer or more than usual, tiredness, vomiting, poor appetite, and weak muscle tone (hypotonia). If untreated, individuals are at risk for developing learning disabilities and developmental delays. Many of these complications can be prevented with early detection and lifelong management with a special diet and appropriate supplements. Many babies are screened for PROP at birth so that treatment can begin early, however the conditions included in newborn screening differ from state to state. For more information, visit Baby’s First Test. PROP is an autosomal recessive trait. A genetic counselor can help you understand the genetics. Talk with your doctor and specialists to decide on the best treatment plan. Support groups are also a good source of information.