Flow results on a patient sample revealed an absence of CD20 and CD19 on the B-lymphocytes as well as an absence of BTK in monocytes and platelets. What is the most likely diagnosis?
A) Hyper IgM syndrome
B) Chronic granulomatous disease
C) Wiskott-Aldrich syndrome
D) X-linked congenital agammaglobulinemia

Question

Quizplus · Accepted Answer

The absence of CD20 and CD19 on B-lymphocytes and BTK in monocytes and platelets suggests a defect in B-cell development and function. This constellation of findings is consistent with X-linked congenital agammaglobulinemia, which is caused by mutations in the Bruton's tyrosine kinase (BTK) gene, an important signaling molecule in B-cell development. Hyper IgM syndrome, chronic granulomatous disease, and Wiskott-Aldrich syndrome would have different flow cytometry results.

Flow Results on a Patient Sample Revealed an Absence of CD20