Galactose (Classical) Epimerase, Blood
About Galactose (Classical) Epimerase, Blood
| Field | Value |
|---|---|
| Also Known As | GALE Test, UDP-Galactose-4-Epimerase Test, Galactose Epimerase Quantitative Test, Galactosemia Type III Test |
| Sample Type | Whole blood |
| Fasting Required | No fasting required |
| Report Time | 7 days |
| Recommended For | Newborns, infants, and individuals with suspected galactose metabolism disorders; all genders and ages |
| Price | Starting at ₹2,950 |
What Is a Galactose (Classical) Epimerase, Blood Test?
The Galactose (Classical) Epimerase, Blood test measures the activity of an enzyme called UDP-galactose-4-epimerase in red blood cells. This enzyme helps the body break down galactose, a sugar found in milk and dairy products.
Doctors order this test when a newborn screening result or a patient's symptoms suggest a problem with galactose metabolism, a condition known as galactosemia type III. The test is also referred to as the GALE test or the UDP-Galactose-4-Epimerase test.
What Does a Galactose (Classical) Epimerase, Blood Test Measure?
This test checks how well the GALE enzyme works inside red blood cells. When functioning normally, this enzyme converts UDP-galactose into UDP-glucose, which cells use for energy. Reduced or absent activity points to a possible enzyme deficiency.
The table below summarises what the test evaluates.
| Parameter | What It Tells Us |
|---|---|
| GALE enzyme activity | How effectively red blood cells convert galactose into a usable form of glucose |
Why Is a Galactose (Classical) Epimerase, Blood Test Done?
Doctors order this Galactose Epimerase test when a patient shows signs that galactose is not being processed correctly. The test helps identify inherited disorders affecting galactose metabolism.
Common Symptoms That May Require This Test
The following symptoms may prompt a doctor to request this test, particularly in newborns and infants.
- Low muscle tone (hypotonia), where the baby appears unusually floppy
- Poor feeding or difficulty latching and feeding
- Vomiting after milk feeds
- Unexplained weight loss or poor weight gain
- Jaundice, which is yellowing of the skin and eyes
- An enlarged liver (hepatomegaly)
- Clouding of the eye lens (cataracts)
Conditions This Test Can Help Detect
A Galactose Epimerase test can assist in identifying the following conditions.
- Epimerase deficiency galactosemia in its three forms: generalised, peripheral, and intermediate
- Galactosemia type III, which may involve cataracts, delayed growth, intellectual disability, liver disease, and kidney problems
- Carrier status for disease-causing variants in the GALE gene
How to Prepare and What to Expect
Preparation for the Galactose Epimerase test procedure is straightforward. The steps below explain what to do before and during the test.
Do You Need to Fast?
No fasting is required before this test, and no special dietary preparation is needed in most cases. However, for infants, collecting the blood sample just before a feed is advisable. This timing prevents recent feeding from spiking galactose metabolites in the blood, ensuring clearer test results.
Practical Tips Before Your Test
The following steps will help ensure accurate results:
- Bring a detailed clinical history including your child's symptoms, previous test results, and family history, as this is required for the test
- Inform the healthcare professional if the patient has recently had a blood transfusion, as this can affect results significantly
- If a transfusion has occurred, wait 3 to 4 months before collecting the sample for this test
- Ensure the sample is kept refrigerated and transported promptly to maintain stability
- Tell your doctor about any medications or supplements the patient is taking
Step-by-Step Procedure
Here is what happens during sample collection for the Galactose Epimerase test:
- A trained healthcare professional cleans the skin at the collection site, usually the inner arm for older patients or the heel for newborns.
- A small blood sample of 3 ml is collected into a green-top sodium heparin tube.
- The tube is labelled and handled carefully. It must not be centrifuged, as the whole blood needs to remain intact.
- The sample is stored at refrigerated temperatures (2 to 8 degrees Celsius) and transported to the laboratory promptly.
- At the specialised laboratory, red blood cells are analysed using fluorometry to measure enzyme activity.
- Results are processed and made available within 7 days.
Factors That Can Affect Accuracy
Several factors can influence the reliability of results:
- A recent blood transfusion, which introduces donor red blood cells and can make enzyme activity appear falsely normal
- Hemolysis, which is the breakdown of red blood cells in the sample
- Improper storage or delayed transport of the specimen
- Feeding immediately before sample collection in infants
- Sample volume being insufficient for analysis
Understanding Your Galactose (Classical) Epimerase, Blood Results
Results from the GALE test must always be reviewed with a qualified doctor alongside the patient's clinical history and other test findings. The table below shows the general reference range used for this test.
| Parameter | Normal Range | Unit |
|---|---|---|
| GALE enzyme activity | 3.5 or above | nmol/hour/mg hemoglobin |
A result at or above the normal threshold is not consistent with galactosemia caused by GALE deficiency. A low result may indicate carrier status, the peripheral form of the condition (where the deficiency is limited to blood cells), or the generalised form (where enzyme activity is severely reduced across tissues). Elevated enzyme activity has no clinical significance and indicates normal enzyme function.
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
Certain situations can change how results should be read:
- Blood transfusion: Enzyme activity measured after a transfusion may reflect the donor's red blood cells rather than the patient's own. This can produce a false-normal result. Testing should be postponed for 3 to 4 months after a transfusion.
- Sample hemolysis or improper storage can reduce the reliability of enzyme activity readings, and the laboratory may need to request a fresh sample.
How to Manage GALE Deficiency
If a GALE deficiency is confirmed, the following general steps are typically recommended by doctors:
- Follow a galactose-restricted diet as directed by your doctor, which involves avoiding milk and dairy products as well as other foods containing galactose
- Read product labels carefully, as galactose is present in many processed foods and medicines
- Attend regular follow-up appointments to monitor health and review any additional tests your doctor recommends
Lupin Diagnostics Galactose (Classical) Epimerase, Blood Price and Home Collection
The Galactose Epimerase test cost at Lupin Diagnostics starts at ₹2,950, and home sample collection is available for this test. The table below shows cities where this test can be booked.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 2950 |
| CHENNAI | 4000 |
| HYDERABAD | 2950 |
| KOLKATA | 2950 |
| NAVI MUMBAI | 2950 |
| PUNE | 2950 |
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 Galactose Epimerase test online:
- Select the test on the Lupin Diagnostics website
- Choose your city and preferred time slot
- Opt for home sample collection by a certified phlebotomist, or visit your nearest Lupin Diagnostics centre
- Receive your report via email or WhatsApp within the stipulated turnaround time
Home Collection
Galactose Epimerase test home collection is available across cities, making it easier for families with newborns or unwell infants to get tested without visiting a centre. All samples are processed in NABL-accredited laboratories by experienced technologists. Digital reports are accessible via email or WhatsApp once ready.
Frequently Asked Questions
This test measures the activity of the UDP-galactose-4-epimerase enzyme in red blood cells. It is used to diagnose a rare inherited disorder called epimerase deficiency galactosemia, also known as galactosemia type III. Doctors order it when a newborn screen or symptoms suggest a problem with how the body handles galactose.
This test is most often ordered for newborns and infants identified as galactosemic through newborn screening, particularly those with elevated total galactose but normal results for another related enzyme (GALT). It is also ordered for individuals showing symptoms such as poor feeding, jaundice, vomiting, or an enlarged liver after consuming milk-based foods.
No fasting is required. For infants, however, it is best to collect the blood sample just before a feed rather than immediately after, as feeding can cause temporary changes in certain readings.
Yes, significantly. Enzyme activity measured in red blood cells after a blood transfusion may reflect the donor's cells rather than the patient's own. This can produce a misleading result. It is important to wait 3 to 4 months after any transfusion before having this test done.
Results for the Galactose Epimerase test are typically available within 7 days. This test is processed in a specialised laboratory, which accounts for the longer turnaround time compared to routine blood tests.
A low result may suggest carrier status for a GALE gene variant, or it may indicate one of the three forms of epimerase deficiency galactosemia. The specific form and its severity are determined by how much enzyme activity is reduced and whether the deficiency is limited to blood cells or affects other tissues. Your doctor will advise on any further testing needed.
There is currently no cure for galactosemia. However, early diagnosis and a galactose-restricted diet, which means avoiding milk, dairy, and foods containing galactose, can help manage the condition effectively. Children diagnosed early and managed with dietary guidance can lead healthy lives. Always follow your doctor's advice for ongoing care.
Galactose (Classical) Epimerase, Blood
