GIST PDGFRA Gene Mutation: Booking, Price, and Results
About GIST PDGFRA Gene Mutation Test
| Field | Value |
|---|---|
| Also Known As | PDGFRA mutation analysis, PDGFRA genotyping, PDGFRA hotspot testing, Platelet-Derived Growth Factor Receptor Alpha mutation test |
| Sample Type | FFPE (formalin-fixed paraffin-embedded) tumour tissue block |
| Fasting Required | No |
| Report Time | 20 days |
| Recommended For | Adults diagnosed with gastrointestinal stromal tumours (GISTs), particularly those being assessed for targeted therapy |
| Price | Starting at ₹10,500 |
What is a GIST PDGFRA Gene Mutation Test?
The GIST PDGFRA gene mutation test is a molecular genetic test that detects mutations in the PDGFRA (Platelet-Derived Growth Factor Receptor Alpha) gene within tumour tissue. It is ordered for patients diagnosed with gastrointestinal stromal tumours (GISTs) to guide treatment decisions. Also known as PDGFRA mutation analysis or PDGFRA genotyping, the test is performed on a tumour tissue sample rather than a routine blood sample.
What Does a GIST PDGFRA Gene Mutation Test Measure?
This test examines specific regions of the PDGFRA gene, known as exons, to identify mutations that influence how a tumour behaves and responds to treatment. Together, these findings help doctors understand which targeted therapies are likely to work and which are not. The table below summarises the analysis:
| Region Tested | What It Represents |
|---|---|
| Exon 18 (activation loop) | The most commonly mutated region, present in approximately 5% of GISTs, includes the D842V mutation |
| Exon 12 (juxtamembrane domain) | A rare mutation site affecting a region with a self-regulating function, seen in roughly 1% of GISTs |
| Exon 14 (ATP-binding domain) | Very rare alteration affecting the energy-binding site of the receptor; found in less than 1% of GISTs |
| D842V mutation (within exon 18) | The single most frequent PDGFRA mutation, which is associated with resistance to imatinib and slower tumour growth |
Why is a GIST PDGFRA Gene Mutation Test Done?
This test is used when a GIST diagnosis has been established, and the treating doctor needs genetic information to plan the next steps in care.
Common Symptoms That May Require This Test
A doctor may order PDGFRA hotspot testing after a GIST is confirmed in patients presenting with the following symptoms:
- Persistent abdominal pain or discomfort
- Gastrointestinal bleeding (blood in stool or vomiting blood)
- A palpable lump or mass in the abdomen
- Feeling full quickly after eating (early satiety)
- Unexplained nausea or vomiting
- Significant fatigue without a clear cause
- Unexplained weight loss
Conditions This Test Can Help Detect
The test is used specifically in the context of GIST and related treatment decisions. It is relevant in the following situations:
- Confirmed gastrointestinal stromal tumours requiring treatment planning
- Assessment of eligibility for tyrosine kinase inhibitor (TKI) therapy, such as imatinib
- Identification of the D842V mutation to determine eligibility for avapritinib, a targeted drug approved for this specific mutation
- Ruling out PDGFRA as a driver mutation when results are negative, prompting evaluation of other mutations such as KIT or BRAF
How to Prepare and What to Expect
This test does not require any special preparation from the patient, as it is performed on a tissue sample already collected during biopsy or surgery.
Do You Need to Fast?
No fasting is required. This test uses a tumour tissue block, not a blood or urine sample, so dietary restrictions do not apply.
Practical Tips Before Your Test
- Bring a detailed clinical history, including your symptoms, previous test results, and family history, as this is required for the test
- Confirm specimen requirements with the laboratory before submitting the tissue block, as these may vary
- Ensure the pathology report from the original biopsy or resection accompanies the specimen
- Confirm that the tissue was fixed using 10% neutral buffered formalin; zinc-based fixatives are not acceptable
- Ask the referring pathologist to mark tumour-rich areas on the block to ensure adequate material for testing
Step-by-Step Procedure
- Tumour tissue is collected during a surgical resection, an endoscopic biopsy, or a core-needle biopsy as part of the original GIST diagnosis.
- The collected tissue is processed into a formalin-fixed, paraffin-embedded (FFPE) block, thereby preserving the tumour material for molecular analysis.
- Where a tissue block is unavailable, 5 to 10 unstained slides cut at 5 or more microns, along with one stained reference slide, may be submitted instead.
- The laboratory extracts genomic DNA from the specimen and amplifies the relevant PDGFRA exons using PCR (a technique that copies specific gene segments for analysis).
- The amplified DNA is analysed using NGS (next-generation sequencing) to detect any mutations.
- A molecular pathologist reviews the findings and issues a written report, which is shared with the referring doctor.
Factors That Can Affect Accuracy
Several factors can influence the reliability of PDGFRA genotyping for TKI selection:
- Low tumour cell content in the specimen (the test requires approximately 10% mutant cells to detect a mutation reliably)
- Poor tissue fixation or use of an incompatible fixative
- Insufficient tumour material in the submitted block or slides
- Tumour heterogeneity, where different areas of the same tumour may carry different mutations
- Previous treatment, which may alter the mutation profile of remaining tumour cells
Understanding Your GIST PDGFRA Gene Mutation Results
Results from this test are reported qualitatively for each exon tested. Your doctor will review the findings alongside your clinical history, imaging results, and pathology report to determine the most appropriate course of action.
| Result | What It Means |
|---|---|
| No mutation detected (wild-type) | PDGFRA does not appear to drive the tumour; testing for KIT, SDH, BRAF, or other mutations may be considered |
| Exon 12 mutation detected | Generally associated with sensitivity to imatinib |
| Exon 14 mutation detected | Generally associated with sensitivity to imatinib |
| Exon 18 mutation detected (non-D842V) | May be sensitive to imatinib; doctor will advise on treatment options |
| Exon 18 D842V mutation detected | Associated with primary resistance to imatinib, avapritinib may be considered |
These ranges are general guidelines. Your doctor will interpret your results based on your age, health history, and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
- Low tumour content in the submitted specimen may produce a false-negative result, meaning a mutation could be missed if there are too few tumour cells present.
- Tumour heterogeneity means that the biopsy sample may not fully represent the mutation profile of the entire tumour, particularly in larger or metastatic tumours.
- Prior systemic treatment may, in some cases, alter detectable mutation patterns in residual or progressive disease.
How to Maintain Healthy Levels
This is a diagnostic test for tumour tissue rather than a routine wellness test, so standard lifestyle advice does not apply in the usual sense. However, the following points are worth keeping in mind:
- Attend all scheduled follow-up appointments with your oncologist after receiving results.
- Report any new or worsening gastrointestinal symptoms to your doctor promptly, as early evaluation can support timely diagnosis.
- Maintaining general health through balanced nutrition and physical activity, as advised by your treating doctor, supports overall well-being during cancer care.
Lupin Diagnostics GIST PDGFRA Gene Mutation Price
The GIST PDGFRA gene mutation test is priced starting at ₹10,500 at Lupin Diagnostics. This test requires a visit to a Lupin Diagnostics centre or submission of the specimen through the centre; home collection is not available for this test.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 10500 |
| CHENNAI | 10500 |
| HYDERABAD | 10500 |
| KOLKATA | 10500 |
| NAVI MUMBAI | 10500 |
| PUNE | 10500 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
- Select the GIST PDGFRA gene mutation test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time to submit specimens.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
The PDGFRA mutation analysis test is a molecular genetic test that detects specific changes in the PDGFRA gene in tumour tissue from a gastrointestinal stromal tumour. It helps doctors confirm the type of mutation driving the tumour and choose the most appropriate targeted therapy.
Knowing the specific mutation present helps predict whether a drug such as imatinib is likely to be effective or whether an alternative, such as avapritinib, should be considered. PDGFRA genotyping for TKI selection is strongly recommended before starting medical therapy for GIST.
The D842V mutation is a specific change in exon 18 of the PDGFRA gene, in which one amino acid is substituted for another. It is the most common PDGFRA mutation in GIST and is associated with imatinib resistance. Patients with this mutation may be eligible for avapritinib, which has shown strong, durable responses in this group.
The test is performed on a formalin-fixed, paraffin-embedded (FFPE) tumour tissue block obtained from a biopsy or surgical resection already performed for GIST diagnosis. A new procedure is generally not required solely for this test.
At Lupin Diagnostics, the report is delivered within 20 days. Some variables, such as specimen quality and laboratory workload, may influence the exact turnaround. Your doctor will inform you when to expect the results.
If both KIT and PDGFRA hotspot testing return negative results, further molecular evaluation is recommended. Your doctor may order additional tests for alternative mutations such as BRAF, NF1, or NTRK gene fusions, which may also respond to specific targeted treatments.
Coverage depends on your insurance provider and policy terms. Since PDGFRA genotyping is recommended in established clinical guidelines for treatment planning in GIST, many insurers do cover it. Contact your insurance provider and the Lupin Diagnostics centre directly to confirm coverage before booking.
GIST PDGFRA Gene Mutation: Booking, Price, and Results
