RNA Testing Reveals 171 MET Exon 14 Skipping Mutations in Lung Cancer

RNA testing has identified 171 distinct mutations that cause MET exon 14 skipping in lung cancer, according to a report by Medical Xpress published July 23, 2026. This discovery allows clinicians to identify a broader range of patients who may benefit from MET-inhibitor therapies by detecting mutations that traditional DNA sequencing often misses.

MET exon 14 skipping occurs when a portion of the MET gene is omitted during protein synthesis, leading to the production of an abnormal protein that promotes tumor growth. While DNA-based testing is the current standard for detecting these alterations, researchers found that analyzing RNA provides a more comprehensive view of the mutations driving the disease.

RNA Testing Increases Detection of MET Mutations

The research detailed by Medical Xpress indicates that RNA sequencing can uncover mutations that are “cryptic” or hidden during standard DNA sequencing. By focusing on the final transcript rather than the genomic blueprint, the testing identified 171 different mutations responsible for the skipping of exon 14.

This method identifies the actual functional impact of a mutation. According to the report, RNA testing confirms whether a DNA mutation actually results in the skipping of the exon, which is the critical driver for the cancer’s progression and the primary target for specific pharmaceutical interventions.

Clinical Implications for Lung Cancer Treatment

The identification of these 171 mutations is significant because patients with MET exon 14 skipping are candidates for MET inhibitors. These targeted therapies are designed to block the overactive MET protein and slow tumor growth.

Because RNA testing captures a wider array of mutations than DNA testing, a larger subset of lung cancer patients may be eligible for these targeted treatments. The findings suggest that some patients previously classified as negative for MET alterations via DNA sequencing may actually possess the skipping mutation when analyzed through RNA.

Distinction Between DNA and RNA Sequencing

DNA sequencing looks for changes in the genetic code, such as deletions or substitutions at the splice sites of the MET gene. However, not every DNA change leads to a functional change in the protein.

RNA sequencing instead examines the messenger RNA (mRNA) produced by the cell. If the mRNA is missing exon 14, the test provides direct evidence of the skipping event regardless of the specific DNA mutation that caused it. This approach effectively bypasses the need to predict the effect of a DNA mutation by observing the result directly.

Future Application in Precision Medicine

The ability to catalog 171 specific mutations provides a detailed map for researchers to further understand how different genetic variations contribute to lung cancer. This data may help refine the selection process for clinical trials and improve the accuracy of companion diagnostics used by oncologists.

While the discovery expands the known landscape of MET mutations, the report emphasizes the role of this testing as a tool for enhancing precision medicine, ensuring that targeted inhibitors are matched to the patients most likely to respond based on their specific molecular profile.