NRG1, MET, RET and Other Rare Fusions: — Where to Get Tested

DNA-based next-generation sequencing can detect some fusions by identifying the structural rearrangement in the DNA, but it misses a meaningful proportion because some breakpoints fall outside the regions the panel captures. RNA sequencing reads the final messenger RNA and directly shows whether two genes have been joined into one abnormal transcript. ESMO and ASCO guidance on fusion detection recommends RNA sequencing or a DNA panel validated for structural variants relevant to the cancer type being tested. If you are unsure what your panel included, ask the laboratory or your oncologist to confirm the method in writing.

Yes. Comprehensive genomic profiling that includes RNA-based fusion detection is available through specialist genomic laboratories operating in India, with processing either domestically or through accredited international partner laboratories. Your oncologist can request this test through CION's referral pathway, and results are returned to your treating team. Tests processed overseas may take longer than domestically processed panels — ask for an expected timeline when the sample is sent so you are not waiting without a clear date.

Costs for comprehensive genomic profiling vary depending on how broad the panel is and whether processing is domestic or international. Costs have fallen significantly in recent years as sequencing technology has become more accessible. Some panel costs may be partially covered under corporate or government health insurance schemes. Ask your oncology team about the options available at the time of your consultation — pricing changes, and the most current information will come directly from the laboratory or your treating centre, not from a general estimate.

Yes — particularly if you have non-small cell lung cancer, thyroid cancer, bile duct cancer, salivary gland cancer, or a cancer that has progressed on standard treatment without a clear molecular driver identified so far. Fusion testing is not yet automatically ordered across all cancer types or all centres. It is reasonable to ask whether a comprehensive genomic profile has been done and whether it included fusion detection. If you are uncertain, a second opinion from a centre with a molecular oncology focus can clarify whether additional testing is appropriate for your situation.

A negative result on a well-validated comprehensive panel means none of the fusions tested were present in the sample sent. It does not mean there is no molecular driver — other alterations such as point mutations, copy number changes or different driver events may be identified on the same report and discussed separately. A negative fusion result also does not rule out all targeted therapy options, because eligibility for some agents is based on other markers such as PD-L1 expression, MSI status or KRAS. Your oncologist will interpret the full report in context, not just the fusion-negative line.

The gene fusions described on this page are almost always somatic — they develop in the tumour cells during a person's lifetime and are not present in normal cells. They are not inherited and do not mean that other family members are at increased risk from the same fusion. This is different from germline mutations such as BRCA1 and BRCA2, which can be inherited and which require a separate type of genetic test. If a family history of cancer concerns you, ask your oncologist about germline genetic counselling — it is a different question from fusion testing on your tumour.