amplification
An increase in gene copy number that can lead to overexpression of oncogenes, often detected through molecular testing and representing potential therapeutic targets.
Full Definition
Gene amplification refers to the duplication of DNA sequences resulting in increased gene copy number, typically involving oncogenes whose overexpression drives cancer progression. Amplifications can range from low-level gains (3-5 copies) to high-level amplifications (>10 copies) and are commonly detected through techniques like FISH, comparative genomic hybridization, or next-generation sequencing. Clinically significant amplifications include HER2 in breast cancer, EGFR in glioblastoma, and MET in various solid tumors. The degree of amplification often correlates with therapeutic response, with higher copy numbers generally associated with greater sensitivity to targeted agents. Editors should understand that amplification differs from overexpression, though they are often correlated.
Usage
Usage note: Distinguish from overexpression (increased mRNA/protein levels) and activation (functional change).
In Context
- "HER2 amplification was confirmed by both FISH and IHC testing." — Molecular pathology report
- "The patient showed EGFR amplification with 8.2 copies per cell." — Genomic profiling result