DMD Carrier Screening (79 Exons) Test
About DMD Carrier Screening (79 Exons) Test
| Field | Value |
|---|---|
| Also Known As | DMD Carrier Screening, Dystrophin Gene Carrier Test, Duchenne/Becker Muscular Dystrophy Carrier Screening, DMD MLPA Test |
| Sample Type | Peripheral blood (EDTA tube) |
| Fasting Required | No |
| Report Time | 15 days |
| Recommended For | Females of reproductive age, especially those with a family history of DMD or BMD, those planning a pregnancy, or those with unexplained elevated creatine kinase levels or muscle symptoms |
| Price | Starting at ₹9,600 |
What is a DMD Carrier Screening (79 Exons) Test?
The DMD carrier screening test checks whether a woman carries a change in the dystrophin gene that could be passed on to her children. The dystrophin gene, known as the DMD gene, contains 79 coding segments called exons. This test examines all 79 of these exons for deletions or duplications using a method called MLPA (Multiplex Ligation-dependent Probe Amplification). It is also called the Duchenne/Becker Muscular Dystrophy Carrier Screening or the DMD MLPA test.
What Does a DMD Carrier Screening (79 Exons) Test Measure?
The DMD carrier screening (79 exons) test analyses the dystrophin gene to look for structural changes that can cause Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD). The following parameters are examined:
| Parameter | What it Means |
|---|---|
| Gene deletions | Missing sections of the DMD gene; account for approximately 60 to 65% of all cases |
| Gene duplications | Extra copies of gene sections; account for approximately 5 to 10% of cases |
| Copy number variations | Changes in the number of copies of specific exons across all 79 exons |
| Carrier status | Whether one copy of the DMD gene carries a pathogenic (disease-causing) variant |
Why is a DMD Carrier Screening (79 Exons) Test Done?
This test is used to identify whether a woman carries a genetic change in the DMD gene that may affect her children or her own health. Below are the key reasons a doctor may recommend it.
Common Symptoms That May Require This Test
Several signs and situations may prompt a doctor to recommend the DMD carrier screening test:
- A family history of Duchenne or Becker muscular dystrophy in male relatives, such as sons, brothers, or uncles
- Unexplained elevation in creatine kinase (CK), a muscle enzyme measured in the blood
- Unexplained muscle weakness or fatigue
- Abnormal gait or difficulty walking
- Cardiac symptoms such as palpitations or reduced heart function
- Enlarged calf muscles without a clear cause
- Planning a pregnancy with concern about inherited genetic conditions
Conditions This Test Can Help Detect
This test identifies carrier status for specific inherited conditions:
- Carrier status for Duchenne muscular dystrophy (DMD), a severe X-linked condition causing progressive muscle weakness
- Carrier status for Becker muscular dystrophy (BMD), a milder form of the same condition
- Risk of dilated cardiomyopathy (a form of heart disease) in female carriers, which affects approximately 8% of carriers
- Inherited risk to offspring, as carrier mothers can pass the condition to sons or the carrier status to daughters
DMD Carrier Screening (79 Exons) Test During Pregnancy
The DMD carrier screening test is an important option for women who are pregnant or planning to become pregnant. Reproductive genetics guidelines recommend offering carrier screening that includes DMD to all women of reproductive age, even if there is no known family history. If a woman is confirmed as a carrier during pregnancy, further prenatal testing (such as chorionic villus sampling or amniocentesis) can determine whether the foetus is affected.
How to Prepare and What to Expect
No special preparation is needed for this test. Here is what you should know before your appointment.
Do You Need to Fast?
No, fasting is not required for the DMD carrier screening (79 exons) test. You may eat and drink normally before sample collection.
Practical Tips Before Your Test
A few simple steps can help make your test as accurate and smooth as possible:
- Bring a detailed clinical history, including your symptoms, previous test results, and family history, as this is required for the test
- If an affected male relative (such as a son or brother) has had a genetic test, bring a copy of their mutation report; this helps the laboratory interpret your results more accurately
- Inform the collecting staff of any medications you are currently taking
- Avoid strenuous exercise 24 to 48 hours before the test if your creatine kinase (CK) levels are also being measured
- No dietary restrictions are needed
Step-by-Step Procedure
The DMD carrier screening test procedure involves a simple blood draw followed by laboratory analysis:
- A small blood sample (2 ml) is collected from a vein in your arm using a standard needle and syringe, into a lavender-topped EDTA tube.
- The sample is labelled, stored at 2 to 8 degrees Celsius, and sent to the laboratory on the same day.
- In the laboratory, genomic DNA is extracted from the white blood cells in your sample.
- The MLPA technique is applied using two probe sets to screen all 79 exons of the DMD gene for deletions and duplications.
- DNA quality is checked and adjusted before analysis begins.
- Specialised software analyses the results to detect any copy number changes across all exons, and a report is prepared by a qualified specialist.
Factors That Can Affect Accuracy
Some factors may influence the reliability of your results:
- MLPA cannot detect point mutations (small changes in a single letter of the genetic code), which cause approximately 25 to 30% of DMD cases; a negative result does not completely rule out carrier status
- Poor sample quality or improper collection into an EDTA tube can affect DNA extraction
- Single-exon deletions may occasionally require additional sequencing to confirm a result
- Prior knowledge of the exact mutation in an affected family member significantly improves interpretation accuracy
Understanding Your DMD Carrier Screening (79 Exons) Test Results
Results from the DMD carrier screening test are reported in the following categories. A qualified doctor or genetic counsellor should always review your results in the context of your personal and family history.
| Result | Interpretation |
|---|---|
| No pathogenic variant detected | Negative; carrier risk is significantly reduced but not completely eliminated, as point mutations are not detected by this method |
| Pathogenic deletion or duplication detected | Positive; confirmed carrier status; genetic counselling is recommended |
| Variant of uncertain significance (VUS) | The finding is unclear; further family testing or additional analysis may be needed |
Disclaimer: 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
Two factors are known to affect how results are interpreted:
- Creatine kinase (CK) levels are raised in approximately 45 to 76% of female carriers, but CK alone is not a reliable way to confirm or rule out carrier status. A normal CK level does not mean a woman is not a carrier.
- Single-exon deletions detected by MLPA may sometimes be false positives caused by genetic variants that affect how the probe binds. Additional sequencing is recommended to confirm these findings before any clinical decision is made.
How to Maintain Healthy Levels
This test identifies carrier status rather than measuring a health marker that can be improved. However, the following general steps support your well-being after testing:
- Carriers are advised to consider early cardiac screening, including an ECG and cardiac imaging, to monitor heart health over time
- Genetic counselling can help you understand your reproductive choices and guide family planning decisions
- Maintaining cardiovascular health through moderate physical activity and a balanced diet is beneficial for everyone, including confirmed carriers
Lupin Diagnostics DMD Carrier Screening (79 Exons) Test Price and Home Collection
The DMD carrier screening test cost at Lupin Diagnostics starts at ₹9,600, and home sample collection is available. The table below lists indicative prices by city.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 9600 |
| CHENNAI | 9600 |
| HYDERABAD | 9600 |
| KOLKATA | 9600 |
| NAVI MUMBAI | 9600 |
| PUNE | 9600 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Booking your DMD carrier screening test online is straightforward:
- 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
Home collection for the DMD carrier screening test is available across cities. A trained phlebotomist visits your home at your chosen time, collects the blood sample, and dispatches it to an NABL-accredited Lupin Diagnostics laboratory. Your digital report is shared with you once ready.
Frequently Asked Questions
The test is recommended for women with a family history of Duchenne or Becker muscular dystrophy in male relatives, including sons, brothers, uncles, or nephews. Women planning a pregnancy, those with unexplained elevated creatine kinase levels, or those with unexplained muscle symptoms should also speak to their doctor about this test.
MLPA (Multiplex Ligation-dependent Probe Amplification) is a laboratory technique that can examine all 79 exons of the dystrophin gene in a single test. It is semi-quantitative, meaning it can detect whether sections of the gene are missing or duplicated, making it well-suited to carrier screening in females.
Yes, though most carriers do not develop symptoms. Approximately 2.5 to 10% of carriers are symptomatic, with symptoms ranging from mild muscle weakness to cardiac involvement such as dilated cardiomyopathy. Regular cardiac monitoring is advisable for confirmed carriers.
A positive result means you carry a pathogenic change in the DMD gene. Your doctor will refer you for genetic counselling to discuss what this means for your health, your reproductive options, prenatal testing possibilities, and whether other female relatives should also be tested.
No. The DMD carrier screening (79 exons) test using MLPA detects deletions and duplications, which account for approximately 70 to 75% of all DMD-causing mutations. Point mutations, which cause the remaining 25 to 30% of cases, are not detected by this method. If your result is negative but clinical suspicion remains, your doctor may recommend additional sequencing.
No fasting is needed. You can eat and drink as normal before the test. The sample is a standard blood draw that can be done at any time of day.
Results are typically available within 15 days from the date of sample collection. This turnaround is standard for genetic tests that require detailed DNA analysis and specialist review.
DMD Carrier Screening (79 Exons) Test
