Final answer:
DiGeorge syndrome affects the immune system, specifically T-cells, due to a chromosomal deletion that impairs the thymus, where T-cells mature, leading to immunodeficiency.
Step-by-step explanation:
DiGeorge syndrome primarily affects T-cells, which are a type of lymphocyte critical for the immune response. Specifically, T-cells are impacted because DiGeorge syndrome is often the result of a deletion on chromosome 22, which includes the DNA that is responsible for the development of the thymus, where T-cells mature. Without a properly functioning thymus, patients with DiGeorge syndrome have significant reductions in their T-cell populations, including T-helper cells, T-suppressor cells, T-cytotoxic cells, and T-delayed type hypersensitive cells. This leads to problems with the immune system's ability to respond to infections and can increase susceptibility to various diseases.
They help in the differentiation of B-cells, which are responsible for producing antibodies. In DiGeorge syndrome, the development and function of both T-cells and B-cells are impaired.