Thymic hypoplsia is seen in which of the following
Correct Answer: Agammaglobulinamia
Description: Ref Robbins 9/e p224 Thymic Hypoplasia: DiGeorge Syndrome DiGeorge syndrome results from a congenital defect in thymic development with deficient T cell maturation. T cells are absent in the lymph nodes, spleen, and peripheral blood, and infants with this defect are extremely vulnera- ble to viral, fungal, and protozoal infections. Patients are also susceptible to infection with intracellular bacteria, because of defective T cell-mediated immunity. B cells and serum immunoglobulins are generally unaffected. The disorder is a consequence of a developmental mal- formation affecting the third and fouh pharyngeal pouches, structures that give rise to the thymus, parathy- roid glands, and poions of the face and aoic arch. Thus, in addition to the thymic and T cell defects, there may be parathyroid gland hypoplasia, resulting in hypocalce- mic tetany, as well as additional midline developmental abnormalities. In 90% of cases of DiGeorge syndrome there is a deletion affecting chromosomal region 22q11, as discussed in Chapter 6. Transplantation of thymic tissue has successfully treated some affected infants. In patients with paial defects, immunity may improve spontane- ously with age.
Category:
Anatomy
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now