A 3-year-old girl is confirmed to have ALL by immunophenotyping. She is positive for the CALLA antigen. Cytogenetic analysis results indicate the presence of the Philadelphia chromosome. Which of the following applies to her?

Question

Quizplus · Accepted Answer

The presence of the Philadelphia chromosome is a poor prognostic indicator in ALL patients. The Philadelphia chromosome is a translocation between chromosomes 9 and 22 that produces the BCR-ABL1 fusion protein, which has tyrosine kinase activity and promotes cell division and inhibition of apoptosis. Targeted therapy with tyrosine kinase inhibitors is effective in patients with the Philadelphia chromosome, but the overall prognosis for these patients is still poor compared to those without the chromosome. The presence of the CALLA antigen is a common finding in ALL and does not affect prognosis. An atypical presentation would be indicated by unusual clinical or laboratory findings, which are not mentioned in the question stem.

A 3-Year-Old Girl Is Confirmed to Have ALL by Immunophenotyping