SNP Shot: Genomic Insights

Activated PI3K-delta syndrome (APDS), a condition affecting the immune system, leads to immune dysfunction. A common characteristic is lymphopenia, a reduced count of white blood cells, especially B and T cells. These cells are vital for fighting off infections by targeting foreign substances like viruses and bacteria. The impact of APDS varies significantly; some individuals experience frequent and severe infections, while others have minimal or no noticeable symptoms.

Recurrent infections, typically beginning in childhood and affecting the lungs, sinuses, and ears, are frequently observed in individuals with APDS. Repeated respiratory infections can result in bronchiectasis, a condition causing damage to the bronchi (airways connecting the windpipe to the lungs), potentially leading to breathing difficulties. Furthermore, those with APDS are susceptible to chronic active viral infections, including Epstein-Barr virus, herpes simplex virus, and cytomegalovirus infections.

Abnormal clumping of white blood cells is another potential manifestation of APDS. This clumping can lead to enlarged lymph nodes (lymphadenopathy) or an enlarged spleen (splenomegaly). Additionally, white blood cells may accumulate and form solid masses (nodular lymphoid hyperplasia), typically in the lining of the airways or intestines. Although nodular lymphoid hyperplasia is non-cancerous, APDS elevates the risk of developing blood cancers such as Hodgkin lymphoma and non-Hodgkin lymphoma.

Autoimmunity, a condition where the body mistakenly attacks its own tissues and organs, can also occur in individuals with activated PI3K-delta syndrome.

There are two forms of activated PI3K-delta syndrome, differentiated by their distinct genetic origins.

Inheritance:

Activated PI3K-delta syndrome follows an autosomal dominant inheritance pattern. This means that only one copy of the mutated gene within each cell is enough to cause the disorder.