Beta Thalassemia-HBB Full Gene (Couple + Prenatal Trio Analysis) Test
About Beta Thalassemia-HBB Full Gene (Couple + Prenatal Trio Analysis) Test
| Field | Value |
|---|---|
| Also Known As | Beta Thalassaemia HBB Gene Sequencing, Beta Globin Gene Trio Analysis, HBB Prenatal Mutation Detection |
| Sample Type | Chorionic villus sample (CVS), amniotic fluid, peripheral blood (both parents), or cord blood |
| Fasting Required | No |
| Report Time | 20 days |
| Recommended For | Couples who are both carriers of beta thalassaemia; pregnant women requiring prenatal diagnosis |
| Price | Starting at ₹15,000 |
What is a Beta Thalassemia-HBB Full Gene (Couple + Prenatal Trio Analysis) Test?
The Beta Thalassemia-HBB Full Gene test analyses the HBB gene in both parents and the foetus to identify mutations that cause beta thalassaemia. It is ordered when both partners are known or suspected carriers of beta thalassaemia and a pregnancy is underway. The test uses blood from each parent alongside a foetal sample, either a chorionic villus sample (CVS) or amniotic fluid. It is also called Beta Thalassaemia HBB Gene Sequencing or HBB Prenatal Mutation Detection.
What Does a Beta Thalassemia-HBB Full Gene (Couple + Prenatal Trio Analysis) Test Measure?
This test sequences the entire HBB gene to identify changes that affect how the body produces beta-globin, a key protein in haemoglobin. The following components are analysed:
| Component | What it Tells Us |
|---|---|
| HBB gene variants | Identifies disease-causing mutations in the beta-globin gene |
| Beta-plus (β+) variants | Mutations that reduce but do not eliminate beta-globin production |
| Beta-zero (β0) variants | Mutations that completely prevent beta-globin production |
| Point mutations, small deletions, and insertions | Account for over 90% of beta thalassaemia cases; detected by gene sequencing |
| Common Indian mutations | Includes del619bp, IVS1-5 G>C, IVS1-1 G>T, codon 8/9 (+G), and codon 41/42 (-TTCT) |
| Foetal inheritance pattern | Compares foetal mutations with parental mutations to determine if the foetus is affected, a carrier, or unaffected |
Why is a Beta Thalassemia-HBB Full Gene (Couple + Prenatal Trio Analysis) Test Done?
This test is specifically designed for carrier couples who are pregnant and need to know whether their unborn child has inherited beta thalassaemia.
Common Symptoms That May Require This Test
A doctor may recommend parental carrier testing when one or more of the following are present:
- Unexplained microcytic anaemia (abnormally small red blood cells)
- Persistent fatigue and pallor without a clear cause
- Abnormal haemoglobin electrophoresis results
- Elevated HbA2 levels on a previous blood test
- A known family history of thalassaemia
- South Asian, Mediterranean, or Middle Eastern ancestry
- A previous pregnancy affected by beta thalassaemia
Conditions This Test Can Help Detect
This test can identify the following conditions in the foetus and in each parent:
- Beta thalassaemia major (also called Cooley's anaemia or transfusion-dependent thalassaemia)
- Beta thalassaemia intermedia (non-transfusion-dependent thalassaemia)
- Beta thalassaemia minor or carrier state (usually without symptoms)
- Compound heterozygous conditions such as HbE/beta thalassaemia and sickle-beta thalassaemia
Beta Thalassemia-HBB Full Gene (Couple + Prenatal Trio Analysis) Test During Pregnancy
This test is specifically performed during pregnancy when both parents are confirmed carriers of the HBB gene mutation. Foetal samples are collected either by CVS in the first trimester (from around 11 weeks) or by amniocentesis from approximately 15 weeks onwards. The results help the couple and their doctors understand whether the foetus has inherited the condition, is a carrier, or is unaffected.
How to Prepare and What to Expect
This test requires careful coordination between both parents and a specialist team. Here is what you need to know before your appointment.
Do You Need to Fast?
No fasting is required for this test. Both parents and the pregnant woman can eat and drink normally before sample collection.
Practical Tips Before Your Test
Please note the following before attending for sample collection:
- Both parents must be present to provide blood samples, as trio analysis requires genetic material from the mother, father, and foetus together.
- Bring a detailed clinical history, including your symptoms, previous test results, and family history, as this is required for the test.
- Carry a valid physician's prescription and any previous haematology or genetic test reports.
- Completed Form G and Prenatal Genetic Testing Consent Form (Form 18) are mandatory; samples are accepted only from registered genetics clinics under the PCPNDT Act.
- Genetic counselling before the procedure is strongly recommended so that the couple understands the implications of the results.
- Inform the clinical team of any medications you are currently taking.
Step-by-Step Procedure
This test involves collecting samples from both parents and the foetus. The procedure is carried out in stages:
Parental Blood Collection (Both Parents)
- A trained phlebotomist will clean the inner elbow area with an antiseptic swab.
- A small volume of blood (3 ml) is drawn from each parent into EDTA tubes (lavender-topped tubes) using a fine needle.
- The blood samples are labelled and stored under refrigeration at 2°C to 8°C for transport.
Foetal Sample Collection (CVS or Amniotic Fluid)
- A specialist doctor collects the foetal sample at a registered genetics clinic. If CVS is chosen, a small piece of placental tissue (approximately 30 mg) is obtained under ultrasound guidance, typically between 11 and 14 weeks of pregnancy. If amniocentesis is chosen, approximately 20 ml of amniotic fluid is drawn using a fine needle under ultrasound guidance, typically from 15 weeks onwards.
- Cord blood (3 ml, collected in an EDTA tube) may also be submitted where applicable.
- All samples are dispatched to the laboratory, where DNA is extracted, the HBB gene is amplified by PCR, and the gene is sequenced using Sanger Sequencing in both directions. Results are delivered within 20 days.
Factors That Can Affect Accuracy
The following factors may influence the reliability of results:
- Poor quality or insufficient foetal sample
- Contamination of the foetal sample with maternal cells
- Improper storage or handling of samples during transport
- Presence of rare or novel HBB mutations not captured by standard sequencing
- Co-inheritance of other globin gene variants that may complicate interpretation
- Large deletions, duplications, or deep intronic variants, which this method may not reliably detect
Understanding Your Beta Thalassemia-HBB Full Gene (Couple + Prenatal Trio Analysis) Test Results
Results are reported as qualitative findings based on the sequencing of the HBB gene. A qualified doctor or genetic counsellor should always review the results alongside clinical and haematological findings.
| Result | Interpretation |
|---|---|
| No pathogenic variant detected | No disease-causing mutation found; individual is not a carrier |
| Heterozygous pathogenic variant | One copy of the mutated gene identified; carrier status (usually without symptoms) |
| Homozygous or compound heterozygous variant | Two mutated gene copies identified; foetus is likely to develop beta thalassaemia major or intermedia |
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.
When both parents carry one mutated HBB gene copy, each pregnancy has a 25% chance of producing an affected child, a 50% chance of producing a carrier, and a 25% chance of producing an unaffected non-carrier child.
Results During Special Conditions
Iron deficiency can produce blood findings that resemble those of thalassaemia. Ferritin levels should be checked to rule out iron deficiency before interpreting results. Additionally, Sanger Sequencing may not reliably detect large deletions, duplications, inversions, or mosaic variants, and further testing may be needed if these are suspected.
How to Maintain Healthy Levels
As this is a genetic test, there are no lifestyle changes that alter gene mutations. However, the following steps support informed decision-making:
- Attend genetic counselling sessions before and after testing to understand what the results mean for your family.
- If both partners are carriers, discuss options such as preimplantation genetic testing with IVF for future pregnancies with a genetic specialist.
- Early prenatal diagnosis allows couples to plan appropriately and access the right clinical support from the start of pregnancy.
Lupin Diagnostics Beta Thalassemia-HBB Full Gene (Couple + Prenatal Trio Analysis) Test Price
The Beta Thalassemia-HBB Full Gene test is available at Lupin Diagnostics starting at ₹15,000. This test requires a visit to a Lupin Diagnostics centre; home collection is not available for this test.
| City | Approximate Price (₹) |
|---|---|
| Mumbai | 6000 |
| Pune | 6000 |
| Bangalore | 6000 |
| Chennai | 6000 |
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 Beta Thalassemia-HBB Full Gene test:
- 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. Ensure both parents attend and carry all required documents.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
This is a genetic test that sequences the entire HBB gene in both parents and the foetus. It identifies mutations responsible for beta thalassaemia and determines whether the unborn child is affected, a carrier, or unaffected. The Beta Thalassemia-HBB Full Gene test is used specifically when both partners are known carriers of beta thalassaemia.
Couples who have both been identified as carriers of the HBB gene mutation should consider this test during pregnancy. It is particularly relevant for families of South Asian, Mediterranean, or Middle Eastern descent, where beta thalassaemia is more prevalent. A doctor or genetic counsellor will advise whether this test is appropriate for your situation.
The foetal sample is collected either by chorionic villus sampling (CVS), typically between 11 and 14 weeks of pregnancy, or by amniocentesis, usually from 15 weeks onwards. Both procedures are performed under ultrasound guidance by a specialist at a registered genetics clinic.
Blood collection from both parents involves minimal discomfort. CVS and amniocentesis carry a small but real risk; approximately one in every hundred procedures may result in a miscarriage. Your doctor will discuss these risks with you in detail before the procedure so that you can make an informed decision.
The report for this test is delivered within 20 days from the date samples are received by the laboratory. The detailed sequencing process requires careful analysis, which accounts for the longer turnaround time.
You will need to bring a physician's prescription, a completed Form G, and a signed Prenatal Genetic Testing Consent Form (Form 18). A detailed clinical history is also required. Samples are accepted only from clinics registered under the PCPNDT Act.
Results should be reviewed with a genetic counsellor or specialist doctor who can explain what the findings mean for your pregnancy. If the foetus is found to be affected, the counsellor will discuss the available options and support pathways. The Beta Thalassemia-HBB Full Gene test cost and the process of obtaining results are best discussed with your doctor or the Lupin Diagnostics team at the time of booking.
Beta Thalassemia-HBB Full Gene (Couple + Prenatal Trio Analysis) Test: Booking, Price, and Results
