Mutation of the gene encoding the enzyme that is essential for the maturation of pre-B cells to mature B lymphocytes is the cause of
A) common variable immunodeficiency
B) isolated IgA deficiency
C) DiGeorge syndrome
D) severe combined immunodeficiency
E) X-linked agammaglobulinemia

Question

Quizplus · Accepted Answer

X-linked agammaglobulinemia (Bruton agammaglobulinemia) is caused by the mutation of Bruton tyrosine kinase (Btk), an enzyme essential for the maturation of pre-B cells into B lymphocytes. Because the defective B lymphocytes cannot produce immunoglobulins, there is agammaglobulinemia and reduced resistance to infections.

Mutation of the Gene Encoding the Enzyme That Is Essential