Spinal Muscular Atrophy Carrier Screening - SMA Test: Booking, Price, and Results
About Spinal Muscular Atrophy Carrier Screening - SMA Test
| Field | Value |
|---|---|
| Also Known As | SMA Carrier Test, SMN1 Gene Carrier Screening, SMN1 Copy Number Analysis, Survival Motor Neuron Gene Test |
| Sample Type | Peripheral blood (EDTA tube) |
| Fasting Required | No fasting required |
| Report Time | 11 days |
| Recommended For | Adults of reproductive age, couples planning pregnancy, pregnant women, partners of known SMA carriers, individuals with a family history of SMA |
| Price | Starting at ₹9,600 |
What Is a Spinal Muscular Atrophy Carrier Screening - SMA Test?
The Spinal Muscular Atrophy Carrier Screening - SMA test is a genetic blood test that checks whether a person carries a faulty copy of the SMN1 gene. SMA (spinal muscular atrophy) is an inherited condition that affects the nerve cells controlling movement. A small blood sample is all that is needed for this test.
Also known as the SMA Carrier Test or SMN1 Copy Number Analysis, this screening is typically recommended for individuals planning a family, pregnant women, and those with a known family history of SMA.
What Does a Spinal Muscular Atrophy Carrier Screening - SMA Test Measure?
This test analyses specific features of the SMN1 gene to determine carrier status. The following parameters are assessed:
| Parameter | What It Tells You |
|---|---|
| SMN1 Exon 7 Copy Number | The number of working copies of the SMN1 gene, which produces a protein essential for motor nerve cell survival |
| SMN2 Exon 7 Copy Number | The number of copies of the backup SMN2 gene, which produces a smaller amount of functional protein |
| g.27134T>G Polymorphism | A genetic marker used to identify "silent carriers" — people who appear to have two normal copies but actually carry none on one chromosome |
The test is performed using MLPA (multiplex ligation-dependent probe amplification), a specialised molecular technique that accurately counts gene copies.
Why Is a Spinal Muscular Atrophy Carrier Screening - SMA Test Done?
This is a preventive screening test, not a diagnostic one. It is offered to people who are healthy but may carry a gene change that could be passed to their children.
Common Reasons This Test Is Requested
Unlike most blood tests, this screening is not triggered by symptoms. It is typically requested in the following situations:
- Planning a pregnancy and wanting to know carrier status
- A family member has been diagnosed with SMA
- A partner has already been identified as an SMA carrier
- A previous pregnancy or child was affected by SMA
- General preconception screening as part of family planning
Conditions This Test Can Help Detect
The SMA carrier screening test helps identify the risk of passing on spinal muscular atrophy (SMA). It is an autosomal recessive neuromuscular disorder, meaning a child must inherit a faulty gene from both parents to be affected. It leads to the breakdown of nerve cells that control movement, causing progressive muscle weakness. SMA has five subtypes based on age of onset and severity, ranging from severe infantile-onset (Type I) to mild adult-onset forms.
Spinal Muscular Atrophy Carrier Screening - SMA Test During Pregnancy
Leading medical bodies recommend that all women who are considering pregnancy or are currently pregnant be offered SMA carrier screening. Having this test before pregnancy gives couples more time to consider their options if both partners are found to be carriers. Copy numbers, namely SMN1 and SMN2, are the key parameters monitored in this context.
How to Prepare and What to Expect
No special preparation is needed before this test. The process is straightforward and involves a routine blood draw.
Do You Need to Fast?
No fasting is required. You can eat and drink normally before the Spinal Muscular Atrophy Carrier Screening - SMA test.
Practical Tips Before Your Test
Keep the following points in mind before your appointment:
- Bring a detailed clinical history, including your symptoms, previous test results, and family history, as this is required for the test.
- Inform your doctor if you have had a whole blood transfusion recently. A waiting period of 10 days post-transfusion is advised before sample collection for genetic testing.
- Inform your healthcare provider of any current medications.
- Genetic counselling before and after testing is strongly recommended to help you understand your results.
- Wear clothing with easy access to your arm for the blood draw.
Step-by-Step Procedure
- A trained phlebotomist (blood collection specialist) will clean the skin on your inner arm with an antiseptic swab.
- A small amount of venous blood (2 mL) is drawn from a vein using a fine needle.
- The blood is collected into a lavender-top EDTA tube, which contains a preservative to protect the DNA.
- The sample is labelled and stored at refrigerated temperature (2 to 8 degrees Celsius) before dispatch.
- The sample is sent to a molecular genetics laboratory, where MLPA analysis is performed on the SMN1 gene.
- Results are processed, and your report is made available within 11 days.
Factors That Can Affect Accuracy
Certain factors may influence the reliability of your results:
- A recent whole blood transfusion can alter DNA analysis — always disclose this to your doctor.
- Using the wrong sample tube (e.g., a heparin or green-top tube) makes the sample unacceptable.
- The quality of DNA extracted from the sample.
- The test has a known limitation: it cannot determine whether two SMN1 copies are on the same chromosome or on separate chromosomes, which can affect carrier risk assessment.
Understanding Your Spinal Muscular Atrophy Carrier Screening - SMA Test Results
Your report will show the number of working SMN1 gene copies detected. A doctor or genetic counsellor should always explain what your result means for your specific situation.
| SMN1 Copy Number | Interpretation | What It May Mean |
|---|---|---|
| 0 copies | Affected | Individual is likely affected with SMA |
| 1 copy | Carrier | One faulty copy present; can be passed to children |
| 2 or more copies | Likely non-carrier | Reduced carrier risk, though a small residual risk remains |
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 situations can affect how results are interpreted:
- Silent carriers are individuals who have two SMN1 copies on the same chromosome and none on the other. Standard MLPA testing may show them as non-carriers, so a residual carrier risk of approximately 1 in 670 remains even with a result of two or more copies.
- Detection rates also vary by ethnicity. The test detects carrier status in approximately 95% of cases in the general population, but this rate may be lower in certain ethnic groups, including individuals of African-American ancestry.
How to Maintain Healthy Levels
SMA is a genetic condition, so lifestyle changes cannot alter carrier status. However, the following steps support informed family planning:
- If you are identified as a carrier, have your partner tested as soon as possible.
- Seek genetic counselling to understand your risk and discuss your reproductive options.
- Early screening, ideally before pregnancy, gives you the most time to make decisions.
Lupin Diagnostics Spinal Muscular Atrophy Carrier Screening - SMA Test Price and Home Collection
The Spinal Muscular Atrophy Carrier Screening - SMA test is available at Lupin Diagnostics starting at ₹9,600, with home sample collection available across cities.
| 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
- 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
The Spinal Muscular Atrophy Carrier Screening - SMA test home collection service is available across multiple cities. All samples are processed in NABL-accredited laboratories by experienced molecular genetics teams. Your digital report is accessible via email or WhatsApp once ready.
Frequently Asked Questions
This test checks whether you carry a faulty copy of the SMN1 gene, which is responsible for causing SMA in children. It is a preventive screening test for individuals planning a family, not a diagnostic test for those with symptoms. Knowing your carrier status helps you and your partner make informed decisions about pregnancy.
Any individual planning a pregnancy or currently pregnant should be offered this screening. Partners of known SMA carriers, people with a family history of SMA, and couples who have previously had an affected child are also advised to get tested.
Being a carrier means you have one working and one faulty copy of the SMN1 gene. Your next step is to have your partner tested. If both of you are carriers, there is a 1-in-4 chance of having a child with SMA and a 1-in-2 chance of having a child who is also a carrier. A genetic counsellor can help you understand your options.
Yes. You can carry the faulty SMN1 gene even if no one in your family has ever been diagnosed with SMA, and even if you have had healthy children before. Many carriers have no symptoms at all and are unaware of their status until they are screened.
Studies in Indian populations suggest that approximately 1 in 30 to 1 in 38 individuals may carry the faulty SMN1 gene. This makes SMA carrier screening particularly relevant for couples planning a family in India.
No. The Spinal Muscular Atrophy Carrier Screening - SMA test can identify whether you and your partner are at risk of having an affected child, but it cannot predict the severity of the condition. SMA severity depends on additional genetic factors, including the number of SMN2 copies. A genetic counsellor can explain what your results mean in more detail.
Spinal Muscular Atrophy Carrier Screening - SMA Test: Booking, Price, and Results
