This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Genes involved in X-Linked SCID- 
Select and explain. 
A. EGFR, B. CD23, C. IL6, D. IL2RG
D: IL2RG
Answer: D: IL2RG 
Explanation: Answer-D. IL2RG* X-linked severe combined immunodeficiency (SCID) is an inherited disorder of the immune system that occurs almost exclusively in males.* Mutations in the IL2RG gene cause X-linked SCID. The IL2RG gene provides instructions for making a protein that is critical for normal immune system function.* Mutations in the IL2RG gene prevent these cells from developing and functioning normally. Without functional lymphocytes, the body is unable to fight off infections.