GJB2 Gene Deafness, autosomal dominant type 3A NGS Genetic Test
Short Name: GJB2 DFNA3A NGS Test
Also known as: DFNA3A Genetic Test, Connexin 26 Gene Test, GJB2 Sequencing Test, Autosomal Dominant Deafness Type 3A NGS Test, GJB2 Mutation Analysis Test
GJB2 Gene Deafness, autosomal dominant type 3A NGS Genetic Test test available at DNA Labs India for ₹20,000. Uses Next-Generation Sequencing (NGS) on Blood or Extracted DNA or One drop Blood on FTA Card samples. Results in Results are typically available within 3 to 4 weeks from the date of sample collection. Reports are delivered via the online portal, email, or WhatsApp.. Free home collection in 300+ cities across India.
🩺 Medically Reviewed By
Dr SULOCHANA HEMCHANDRA HOLLA
Consultant Medical Geneticist · Reg: 8532
Last reviewed: September 7, 2026
Overview
The primary purpose of this genetic test is to detect pathogenic mutations in the GJB2 gene that are associated with autosomal dominant non-syndromic hearing loss type 3A (DFNA3A). Identifying the specific genetic cause of hearing loss enables accurate diagnosis, appropriate clinical management, informed family planning decisions, and genetic counseling for at-risk family members. The test also helps differentiate DFNA3A from other forms of genetic hearing loss, guiding personalized treatment strategies.
- Test Code
- 2318
- CPT Code
- 81479
- ICD Code
- H90.5
- Price
- ₹20,000
- Sample Type
- Blood or Extracted DNA or One drop Blood on FTA Card
- Result Time
- Results are typically available within 3 to 4 weeks from the date of sample collection. Reports are delivered via the online portal, email, or WhatsApp.
- Fasting Required
- No
- Method
- Next-Generation Sequencing (NGS)
Sample Collection
No special preparation such as fasting is required. Inform your referring physician about your complete medical history, current medications, and any recent blood transfusions. A pre-test genetic counseling session is strongly recommended to understand the implications of testing, the possible outcomes, and how results may affect you and your family members.
Method: Venipuncture
Laboratory Analysis
A trained phlebotomist will collect approximately 3 to 5 mL of peripheral blood from a vein in your arm using standard venipuncture technique. Alternatively, extracted DNA or one drop of blood on an FTA card may be submitted. The collection procedure typically takes 5 to 10 minutes and is associated with minimal discomfort.
Report Delivery
Apply gentle pressure to the puncture site with a sterile cotton ball for 3 to 5 minutes. You may resume normal daily activities immediately. The blood sample is transported to the DNA Labs India laboratory under appropriate conditions for DNA extraction and NGS analysis. Results will be available within 3 to 4 weeks through the online portal, email, or WhatsApp.
Timeline: Results are typically available within 3 to 4 weeks from the date of sample collection. Reports are delivered via the online portal, email, or WhatsApp.
Patient Instructions
About This Test
Who Should Get This Test
The primary purpose of this genetic test is to detect pathogenic mutations in the GJB2 gene that are associated with autosomal dominant non-syndromic hearing loss type 3A (DFNA3A). Identifying the specific genetic cause of hearing loss enables accurate diagnosis, appropriate clinical management, informed family planning decisions, and genetic counseling for at-risk family members. The test also helps differentiate DFNA3A from other forms of genetic hearing loss, guiding personalized treatment strategies.
How to Prepare
- Collect 3 to 5 mL of peripheral blood in an EDTA (lavender top) vacutainer tube
- Alternatively, submit extracted DNA or one drop of blood on an FTA card
- Label the sample clearly with the patient's full name, date of birth, and unique identification number
- Ensure the sample is not hemolyzed; avoid vigorous shaking of the blood tube
- Store the blood sample at ambient room temperature (15-30°C) until dispatch
- Dispatch the sample to the laboratory within 48-72 hours of collection
- Include the duly filled test requisition form and clinical history
Doctor's Notes
Reviewed by Dr SULOCHANA HEMCHANDRA HOLLA — MBBS, MD (Medical Genetics) · Reg. No. 8532
"As an ENT specialist, I frequently encounter patients with progressive bilateral hearing loss that has a genetic basis. The GJB2 gene, encoding connexin 26, is one of the most commonly implicated genes in hereditary deafness worldwide. When I identify a patient with bilateral sensorineural hearing loss and a family history consistent with autosomal dominant inheritance, I recommend the GJB2 DFNA3A NGS genetic test. Early identification of the genetic cause allows for timely intervention with hearing aids or cochlear implants and enables genetic counseling for at-risk family members. I strongly advise genetic counseling both before and after testing so that patients and families can fully understand the implications of the results, including recurrence risks for future generations."
Last medically reviewed: September 7, 2026
Test Parameters & Specifications
Sample Stability
- Insufficient sample volume (less than 2 mL of blood)
- Severely hemolyzed or clotted blood sample
- Sample received without proper labeling or identification
- Contaminated DNA sample
- Sample received without a duly completed test requisition form
- Sample transported or stored under improper conditions
Understanding Your Results
Pathogenic or Likely Pathogenic Variant Detected
A disease-causing or likely disease-causing mutation in the GJB2 gene associated with DFNA3A has been identified. This confirms the genetic basis of the patient's hearing loss and indicates autosomal dominant inheritance. Each first-degree relative has a 50% chance of carrying the same variant. Genetic counseling is recommended for the patient and family members.
No Pathogenic Variant Detected
No known pathogenic or likely pathogenic mutations in the GJB2 gene were identified by this test. This result does not completely exclude a genetic basis for hearing loss, as mutations in other genes (e.g., GJB6, SLC26A4, TMC1, TMPRSS3, and others) may be responsible. A comprehensive hearing loss gene panel or clinical evaluation may be considered.
Variant of Uncertain Significance (VUS) Identified
A genetic variant in the GJB2 gene was detected, but current evidence is insufficient to classify it as pathogenic or benign. This result should not be used alone for clinical decision-making. Family segregation studies, functional studies, and periodic re-evaluation as new evidence becomes available are recommended. Genetic counseling is advised.
Consult your doctor or a clinical geneticist if you or your family members experience progressive or unexplained hearing loss, have a family history of hereditary deafness across multiple generations, or if the test results indicate a pathogenic or likely pathogenic variant in the GJB2 gene. Early consultation enables timely intervention with hearing aids, cochlear implants, or other assistive devices, and allows for appropriate genetic counseling for reproductive planning.
Limitations
- ⚠This test specifically targets the GJB2 gene only; other genetic causes of hearing loss will not be detected
- ⚠Large genomic rearrangements, deep intronic mutations, or regulatory region variants may not be identified by standard NGS sequencing
- ⚠Variants of uncertain significance (VUS) may be reported, requiring further evaluation and family studies
- ⚠This test does not predict the severity, age of onset, or rate of progression of hearing loss
- ⚠A negative result does not completely exclude a genetic basis for hearing loss as other genes may be involved
Risks & Considerations
- ●Minimal risk associated with blood collection, including slight bruising, pain, or swelling at the puncture site
- ●Potential psychological or emotional impact of receiving genetic test results, particularly if a pathogenic variant is identified
- ●Risk of identifying variants of uncertain significance (VUS) that may cause anxiety without providing definitive answers
- ●Implications for insurance and employment should be considered, though genetic information is protected under applicable privacy laws
Interfering Factors
- ●Hemolyzed blood sample may reduce DNA quality and affect sequencing accuracy
- ●Recent blood transfusion within the past 3 months may interfere with the patient's own DNA profile
- ●Contaminated or improperly stored DNA sample may yield inaccurate or inconclusive results
- ●Concurrent use of certain medications is unlikely to affect results but should be disclosed to the testing laboratory
Compare With Similar Tests
| Test | GJB2 Gene Deafness, autosomal dominant type 3A NGS Genetic Test | GJB2 Gene Deafness, Autosomal Recessive Type 1A (DFNB1A) NGS Genetic Test | Comprehensive Hearing Loss Gene Panel NGS Test | GJB6 Gene Deafness NGS Genetic Test | SLC26A4 Gene Pendred Syndrome / DFNB4 NGS Genetic Test |
|---|---|---|---|---|---|
| Comparison | GJB2 Gene Deafness, autosomal dominant type 3A NGS Genetic Test |
Frequently Asked Questions
What is GJB2 gene deafness autosomal dominant type 3A (DFNA3A)?
How is the GJB2 DFNA3A NGS genetic test performed?
What sample is required for this genetic test?
How long does it take to get the test results?
Who should consider getting the GJB2 DFNA3A genetic test?
What does a positive test result mean?
Is genetic counseling recommended before and after the test?
Can this test be performed on children?
Is the GJB2 genetic test covered by insurance in India?
What is the difference between autosomal dominant and autosomal recessive GJB2 deafness?
Are there treatment options available after diagnosis?
Can I get this test done from home?
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