The major defect in X-linked severe combined immunodeficiency (SCID) is:
A) Inability to produce IL-2
B) Lack of ZAP-70 protein kinase
C) Inability to produce B or T cells
D) Lack of g-chain in interleukin receptors

Question

Quizplus · Accepted Answer

In X-linked SCID, a genetic defect renders the patient unable to produce g-chains, which are key components of a variety of different interleukin receptors, most notably the IL-2 receptor. The absence of these receptors is significant because when exposed to a pathogen, activation of lymphocytes, synthesis of antibodies, and NK cell development are impaired, which is very dangerous for the patient. Most infants with this disorder die from infections within 1 year.

The Major Defect in X-Linked Severe Combined Immunodeficiency (SCID) Is