Chromosome 17p deletion
A high-risk cytogenetic abnormality involving loss of the p53 tumor suppressor gene, associated with poor prognosis in CLL.
Full Definition
Chromosome 17p deletion, specifically del(17p), results in loss of the TP53 gene located on the short arm of chromosome 17. This cytogenetic abnormality is found in approximately 5-10% of treatment-naive CLL patients and up to 40% of relapsed cases. Loss of p53 function renders cancer cells resistant to DNA damage-induced apoptosis, leading to chemotherapy resistance and aggressive disease behavior. Patients with del(17p) have significantly shorter progression-free survival with standard chemoimmunotherapy and require alternative treatment approaches such as BTK inhibitors or BCL-2 inhibitors.
Usage
Usage note: Always specify percentage of cells affected; distinguish from TP53 mutations which may coexist.
In Context
- "FISH analysis revealed del(17p) in 85% of analyzed nuclei, confirming high-risk cytogenetics." — Cytogenetic analysis report
- "Given the presence of chromosome 17p deletion, ibrutinib was selected over fludarabine-based chemotherapy." — Treatment selection rationale