PDGFRA-FIP1L1 Gene Rearrangement FISH Test: Booking, Price, and Results
About PDGFRA-FIP1L1 Gene Rearrangement FISH Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | FIP1L1-PDGFRA fusion test, PDGFRA rearrangement FISH, HES/leukaemia 4q12 (CHIC2) deletion, FIP1-like-1/platelet-derived growth factor alpha receptor gene rearrangement |
| Sample Type | Bone marrow (preferred) and peripheral blood |
| Fasting Required | No fasting required |
| Report Time | 8 days |
| Recommended For | Adults with unexplained persistent high eosinophil counts; more common in males |
| Price | Starting at ₹9,400 |
What Is a PDGFRA-FIP1L1 FISH Test?
The PDGFRA-FIP1L1 FISH test is a specialised molecular test that detects an abnormal fusion of two genes on chromosome 4. This fusion causes the bone marrow to overproduce eosinophils, a type of white blood cell. Doctors order this test when a patient has persistently elevated eosinophil levels with no obvious cause. The test uses a technique called fluorescence in situ hybridisation (FISH), which identifies specific changes in DNA using fluorescent probes. It may also be referred to as the FIP1L1-PDGFRA fusion test or the CHIC2 deletion test.
What Does a PDGFRA-FIP1L1 FISH Test Measure?
This test looks for specific genetic changes associated with eosinophilic blood disorders. The two main things it examines are listed below.
| What Is Measured | What It Measures |
|---|---|
| FIP1L1-PDGFRA fusion gene | An abnormal joining of two genes that results in uncontrolled eosinophil production |
| CHIC2 deletion | Loss of a small region on chromosome 4 that signals the presence of the FIP1L1-PDGFRA fusion |
The CHIC2 region sits between the FIP1L1 and PDGFRA genes. When this region is deleted, the two flanking genes merge and create a constantly activated protein that drives abnormal cell growth. This deletion is too small to be seen by standard chromosome analysis, which is why FISH is required.
Why Is a PDGFRA-FIP1L1 FISH Done?
This test is ordered when a doctor suspects an underlying genetic cause for a patient's raised eosinophil count. Below are the common reasons it may be requested.
Common Symptoms That May Require This Test
Patients who need this test often present with a combination of the following symptoms:
- Persistent fatigue without a clear cause
- Skin rash or itching (pruritus)
- Cough and breathlessness
- Unexplained fever
- Unexplained weight loss
Conditions This Test Can Help Detect
The PDGFRA-FIP1L1 FISH test can help identify several haematological conditions, including:
- Chronic eosinophilic leukaemia (CEL), the most common context for this fusion gene.
- Myeloid or lymphoid neoplasms with eosinophilia and PDGFRA rearrangement.
- Systemic mast cell disease associated with eosinophilia.
- Acute myeloid leukaemia or T-lymphoblastic lymphoma in some cases.
- Idiopathic hypereosinophilic syndrome, where this test rules out a clonal genetic cause.
PDGFRA-FIP1L1 FISH Test for Chronic Disease Monitoring
Patients diagnosed with FIP1L1-PDGFRA-positive eosinophilic disorders are often treated with targeted therapy and require regular follow-up. Molecular monitoring is recommended every three months during the first two years of treatment and every three to six months thereafter. This helps confirm whether treatment is working and whether a molecular response has been achieved.
How to Prepare and What to Expect
No complex preparation is needed for this test. The steps below explain what to expect before and during sample collection.
Do You Need to Fast?
No, fasting is not required for this test. You may eat and drink as normal before your appointment.
Practical Tips Before Your Test
Keep the following points in mind before going for sample collection:
- Bring a detailed clinical history, including your symptoms, previous test results, and family history, as this information is important for test interpretation.
- Inform your doctor about all current medications, including supplements and blood thinners.
- Stay well hydrated, as this helps with blood draws.
- Wear a loose-fitting top or shirt with easy arm access.
- Avoid strenuous physical activity on the day of collection.
Step-by-Step Procedure
This test requires two types of samples: peripheral blood and bone marrow. Here is what the collection process involves.
Peripheral Blood Collection:
- A trained phlebotomist cleans a vein in your arm with an antiseptic.
- A needle is inserted to draw approximately 3 mL of blood into a lavender-top EDTA tube.
- The tube is labelled and prepared for transport.
Bone Marrow Collection:
- The skin over your hip bone (or another suitable site) is cleaned, and a local anaesthetic is applied.
- A specialist inserts a needle into the bone marrow cavity to withdraw approximately 3 mL of bone marrow into a green-top sodium heparin tube.
- The tube is gently inverted several times to prevent clotting.
- Both samples are stored between 2 and 8 degrees Celsius and dispatched to the laboratory promptly for FISH analysis.
Factors That Can Affect Accuracy
Several factors may influence the quality of the test result:
- Delayed transport (samples should reach the lab within 24 to 48 hours of collection)
- Clotted or poorly preserved specimens
- Insufficient sample volume
- Use of an incorrect anticoagulant tube
- Very low numbers of abnormal cells, which may reduce detection sensitivity
Understanding Your PDGFRA-FIP1L1 FISH Test Results
Results from this test are qualitative, meaning they are reported as detected or not detected rather than as a number. Your doctor will review the interpretive report alongside your full clinical picture.
| Result | Interpretation |
|---|---|
| Fusion not detected (negative) | No evidence of FIP1L1-PDGFRA rearrangement or CHIC2 deletion was identified. This makes a PDGFRA-rearranged eosinophilic neoplasm unlikely, although clinical correlation is required. |
| Fusion detected (positive) | FIP1L1-PDGFRA rearrangement and/or CHIC2 deletion was identified. This supports the diagnosis of a clonal eosinophilic disorder, such as chronic eosinophilic leukaemia or a related myeloid neoplasm. |
Disclaimer: These interpretations are provided as general guidance. 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
Standard chromosome analysis (karyotyping) cannot detect the FIP1L1-PDGFRA fusion because the deletion involved is only around 800 kilobases in size. Most patients with this fusion have an apparently normal karyotype. FISH is the appropriate method for detecting this change. In cases where the clone size is very small, even FISH may occasionally miss a low-level abnormality.
How to Maintain Healthy Levels
While this is a genetic test and lifestyle changes cannot alter the result, the following general steps support overall wellbeing during follow-up:
- Attend all scheduled haematology follow-up appointments and repeat tests as advised.
- Report any new or worsening symptoms to your doctor promptly.
- Maintain a balanced diet, adequate rest, and routine health check-ups.
Lupin Diagnostics PDGFRA-FIP1L1 FISH Test Price
The PDGFRA-FIP1L1 FISH test is priced starting at ₹9,400 at Lupin Diagnostics. Due to the specialised nature of this test, sample collection requires a visit to a Lupin Diagnostics centre. Home collection is not available for this test.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 9400 |
| CHENNAI | 9400 |
| HYDERABAD | 9400 |
| KOLKATA | 9400 |
| NAVI MUMBAI | 9400 |
| PUNE | 9400 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Follow these steps to book your PDGFRA-FIP1L1 FISH test online:
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time for sample collection.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
The FIP1L1-PDGFRA fusion forms when a small segment of chromosome 4 is deleted, causing two normally separate genes to join together. The resulting abnormal protein is permanently switched on, sending continuous signals for cell growth. This leads to an uncontrolled rise in eosinophils in the blood and bone marrow.
This test is most often ordered for adults between the ages of 20 and 50 who have persistently high eosinophil levels. The condition is significantly more common in men, with a male-to-female ratio of approximately 9:1. A haematologist typically requests the PDGFRA-FIP1L1 FISH test after ruling out common causes of eosinophilia such as allergies or parasitic infections.
A positive result confirms the presence of the FIP1L1-PDGFRA fusion gene. This finding is associated with conditions such as chronic eosinophilic leukaemia or related myeloid neoplasms. Your doctor will discuss the next steps, which typically involve further evaluation and a treatment plan.
No. The PDGFRA-FIP1L1 FISH test procedure requires strict specimen handling and, in most cases, bone marrow collection by a trained specialist. For these reasons, sample collection must take place at a Lupin Diagnostics centre or hospital. Home collection is not available for this test.
At Lupin Diagnostics, the report is delivered within 8 days of sample collection. FISH-based tests involve several laboratory steps, including cell preparation, probe hybridisation, and microscopic analysis, which take time to complete accurately.
The deletion responsible for the FIP1L1-PDGFRA fusion is very small (approximately 800 kilobases) and cannot be seen under a standard microscope during routine chromosome analysis. FISH uses fluorescent probes that bind directly to the specific DNA regions of interest, making it sensitive enough to detect this otherwise invisible change.
Yes. Clinical history is required for this test. Please bring a summary of your symptoms, any previous blood test reports showing elevated eosinophil counts, details of your current medications, and any relevant medical records. This information helps the pathologist interpret your results accurately.
PDGFRA-FIP1L1 Gene Rearrangement FISH Test: Booking, Price, and Results
