Question

A patient with hyper-IgM syndrome likely has a defect in:

• A. RAG-1/2
• B. CD40 ligand
• C. IL-2 receptor
• D. NADPH oxidase

Hint:

When studying immunodeficiencies, pay attention to the specific molecular defects that lead to dysfunctional immune responses, like CD40 ligand mutations in hyper-IgM syndrome.

Answer 1

The Correct Option is B

Hyper-IgM syndrome is a primary immunodeficiency disorder that is commonly caused by a defect in the CD40 ligand. This defect results in a failure of proper T-cell signaling, leading to defects in immunoglobulin class switching, which is why patients with hyper-IgM syndrome have elevated levels of IgM and low levels of other antibodies. The other listed options are not typically associated with this syndrome.