Thymic Aplasia is a medical condition characterized by the underdevelopment or absence of the thymus, an organ crucial for the development of the immune system. The thymus plays a vital role in producing T-cells, which help the body fight infections. When this organ is absent or not functioning properly, individuals may experience a weakened immune response. This condition is often associated with DiGeorge syndrome, a genetic disorder that can lead to various health issues, including heart defects and facial abnormalities. Diagnosis typically involves imaging studies and blood tests to assess immune function. Treatment may include immunotherapy and management of infections.