Activated Phosphoinositide 3-kinase Delta Syndrome [APDS]

This code identifies Activated Phosphoinositide 3-kinase Delta Syndrome (APDS), a rare primary immunodeficiency characterized by recurrent infections, lymphoproliferation, and an increased risk of lymphoma. It is an autosomal dominant disorder resulting from gain-of-function mutations in the PIK3CD or PIK3R1 genes, leading to dysregulation of the PI3K/AKT/mTOR pathway.

Assign this code for patients with a confirmed diagnosis of APDS, typically established through genetic testing identifying pathogenic variants in PIK3CD or PIK3R1. Documentation should reflect the clinical manifestations consistent with APDS, such as recurrent sinopulmonary infections, chronic lymphadenopathy, splenomegaly, and/or autoimmune phenomena.

• Ensure genetic testing results or a definitive clinical diagnosis by an immunologist are present in the medical record.
• Do not confuse with other primary immunodeficiencies unless APDS is specifically ruled out or co-occurs.
• Code any associated complications, such as infections or malignancies, in addition to this primary diagnosis.