APDS, previously known as PASLI disease*, is a type of rare primary immunodeficiency, recently discovered in 2013. Being rare, this condition affects approximately 1 to 2 people per million worldwide. In the United States, it is estimated that there are about 400 to 600 individuals living with APDS. More individuals are anticipated to be identified with the increased availability of genetic testing for APDS.2
Primary immunodeficiencies are a group of genetic disorders that impair the body’s immune system function making it difficult to fight off infections. APDS is caused by an faulty gene that plays a key role in B and T cell development. Normally, B and T cells fight infections, but in APDS, these cells are not fully formed or healthy enough to fight infections properly. APDS also causes an overproduction of these defective B and T cells which then causes a buildup of these cells in various lymph nodes and organs.1
People with APDS are vulnerable to frequent infections, especially in the ears, sinuses, and respiratory tracts. People with APDS may also experience swollen lymph nodes or an enlarged spleen along with a higher risk of developing cancers such as lymphoma.1