Activated Phosphatidylinositol-3-OH Kinase Delta Syndrome

**Semantic type:** Disease or Syndrome

**Definition:** A rare, autosomal dominant inherited primary immunodeficiency disorder caused by mutations in either PIK3CD gene or PIK3R1 gene. Clinical manifestations include the following: recurrent respiratory tract infections; non-malignant lymphoproliferation that results in generalized lymphadenopathy and hepatosplenomegaly; chronic infections with Epstein-Barr virus, cytomegalovirus, and herpes simplex virus; cytopenia; and glomerulonephritis. Patients are at an increased risk of developing non-Hodgkin or Hodgkin lymphoma.

**Synonyms:** - APDS - Activated PI3 Kinase Delta Syndrome - Activated PI3K Delta Syndrome - Activated PI3K-Delta Syndrome - Activated Phosphoinositide 3-Kinase Delta Syndrome