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GNB4 Gene CMTDIF NGS Genetic Test

DNA Labs India | ISO 9001:2015 Certified

GNB4 Gene CMTDIF NGS Genetic Test

Short Name: GNB4 CMTDIF NGS

Also known as: GNB4 Gene NGS Test, CMTDIF Genetic Test, Charcot-Marie-Tooth Disease NGS Panel

GNB4 Gene CMTDIF 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 The genetic test report will be ready within 3 to 4 weeks after sample submission. Urgent processing may be available upon request.. Free home collection in 300+ cities across India.

NGS Genetic Test🏠 Home Collection

✍️ Written By

🩺 Medically Reviewed By

Dr SULOCHANA HEMCHANDRA HOLLA

Dr SULOCHANA HEMCHANDRA HOLLA

Consultant Medical Geneticist · Reg: 8532

Last reviewed: September 7, 2026

Overview

The primary purpose of the GNB4 Gene CMTDIF NGS Genetic Test is to identify pathogenic or likely pathogenic variants in the GNB4 gene that are known to cause CMTDIF. The test is indicated for individuals showing symptoms such as distal muscle weakness, foot deformities, sensory loss, or a family history of Charcot-Marie-Tooth disease. Early genetic diagnosis can facilitate appropriate management, rehabilitation, and informed reproductive decisions. The test also aids in ruling out other genetic causes of hereditary neuropathy.

Test Code
3970
ICD Code
G60.0
Price
₹20,000
Sample Type
Blood or Extracted DNA or One drop Blood on FTA Card
Result Time
The genetic test report will be ready within 3 to 4 weeks after sample submission. Urgent processing may be available upon request.
Fasting Required
No
Method
Next Generation Sequencing (NGS)
Step 1

Sample Collection

No special preparation such as fasting is required. Keep the clinician informed about any ongoing medications or previous genetic testing.

Method: Venipuncture or Finger-prick blood collection

Step 2

Laboratory Analysis

A standard blood sample is collected from a vein in your arm. If using FTA card, a simple finger-prick is sufficient. The procedure is quick and minimally invasive.

Step 3

Report Delivery

You can resume normal activities immediately. The sample will be transported to our laboratory for NGS analysis. You may be asked to provide your clinical history and family pedigree.

Timeline: The genetic test report will be ready within 3 to 4 weeks after sample submission. Urgent processing may be available upon request.

Patient Instructions

1
Before the Test:No fasting required. Maintain a list of any other tests or genetic findings that may be relevant.
2
During the Test:A single blood sample is collected. For FTA card, only a fingerprint amount of blood is needed.
3
After the Test:Your blood sample is sent to the lab for NGS analysis. You will receive a notification when the report is ready, typically in 3-4 weeks.

About This Test

Who Should Get This Test

The primary purpose of the GNB4 Gene CMTDIF NGS Genetic Test is to identify pathogenic or likely pathogenic variants in the GNB4 gene that are known to cause CMTDIF. The test is indicated for individuals showing symptoms such as distal muscle weakness, foot deformities, sensory loss, or a family history of Charcot-Marie-Tooth disease. Early genetic diagnosis can facilitate appropriate management, rehabilitation, and informed reproductive decisions. The test also aids in ruling out other genetic causes of hereditary neuropathy.

How to Prepare

  • Use an EDTA vacutainer for whole blood collection (2 ml minimum)
  • If using FTA card, apply one drop of blood onto the marked circle and air dry for 30 minutes
  • Label the sample with patient name, date, and unique ID
  • Store blood at 2-8°C if immediate dispatch is not possible
  • Ship the sample in a leak-proof container with proper packaging

Doctor's Notes

Reviewed by — MBBS, MD (Medical Genetics) · Reg. No. 8532

"Genetic confirmation plays a critical role in family planning and early management of inherited neuropathies like CMTDIF."

Last medically reviewed: September 7, 2026

Test Parameters & Specifications

Sample TypeBlood or Extracted DNA or One drop Blood on FTA Card
Sample Volume2 ml whole blood or 1-2 µg extracted DNA or 1 FTA card spot
ContainerEDTA vacutainer / DNA vial / FTA card
Collection MethodVenipuncture or Finger-prick blood collection

Sample Stability

Whole blood in EDTA72 hours
Extracted DNA6 months
FTA card blood spot1 year
Sample Rejection Criteria:
  • Hemolyzed or severely clotted blood sample
  • Sample with incorrect patient identifier
  • Sample transported in improper container
  • Sample exposed to extreme heat or frozen whole blood

Understanding Your Results

The test report will be interpreted by a clinical geneticist. Results are classified according to the American College of Medical Genetics and Genomics (ACMG) guidelines.
Positive result: A pathogenic or likely pathogenic variant in the GNB4 gene confirms the molecular diagnosis of CMTDIF.
Negative result: No pathogenic variant found in the GNB4 gene. This does not completely exclude CMTDIF if clinical suspicion is high; additional gene tests may be advised.
VUS (Variant of Uncertain Significance): A variant has been identified but its clinical significance is not yet clear. Further family segregation studies may be recommended.
⚠️ When to Consult a Doctor:

If the test report identifies a pathogenic variant, please consult a neurologist or a clinical geneticist to discuss the findings and implications. If a VUS is reported, a genetic counsellor will guide you regarding additional testing and family studies.

Limitations

  • ⚠This test detects only pathogenic variants in the GNB4 gene and does not rule out other genes associated with CMT
  • ⚠NGS may not reliably detect large deletions, duplications, repeat expansions, or deep intronic variants
  • ⚠Variants of uncertain significance may be reported and require further investigation
  • ⚠Clinical correlation is essential for final diagnosis

Risks & Considerations

  • ●No significant physical risks are associated with blood collection.
  • ●Minor bruising or discomfort at the puncture site may occur.
  • ●A small risk of infection exists with any blood draw, although standard protocols minimise this risk.

Interfering Factors

  • ●Contamination of the sample with foreign DNA
  • ●Incorrect sample labelling or handling
  • ●Sample degradation due to prolonged storage at room temperature
  • ●Presence of a haematological malignancy or recent allogeneic bone marrow transplant may interfere with interpretation

Compare With Similar Tests

TestGNB4 Gene CMTDIF NGS Genetic TestWhole Exome Sequencing (WES)PMP22 duplication/deletion test
ComparisonGNB4 Gene CMTDIF NGS Genetic Test

Frequently Asked Questions

What is the GNB4 Gene CMTDIF NGS Genetic Test?
This is a targeted next-generation sequencing test that analyses the GNB4 gene for mutations associated with Charcot-Marie-Tooth disease type DIF (CMTDIF).
Why should I undergo this genetic test?
If you or your family members exhibit symptoms such as distal muscle weakness, foot deformities, or sensory loss, this test can provide a molecular diagnosis for CMTDIF and help guide management.
What sample is required?
A blood sample obtained by venipuncture, or extracted DNA, or one drop of blood on an FTA card is acceptable. No fasting is needed.
How long does it take to receive my report?
The turnaround time is typically 3 to 4 weeks from the time the sample reaches our laboratory.
What does a positive result mean?
A positive result indicates the presence of a pathogenic or likely pathogenic variant in the GNB4 gene, which confirms the clinical diagnosis of CMTDIF.
What does a negative result mean?
A negative result means no pathogenic variant was detected in the GNB4 gene. However, it does not rule out CMTDIF or other genetic neuropathies, and further testing may be recommended.
Will my insurance cover this test?
Coverage varies by insurance provider and policy. We recommend checking with your insurance company. Our team can provide necessary documents and guidance for reimbursement.
Can this test detect all types of Charcot-Marie-Tooth disease?
No, this test specifically targets only the GNB4 gene. For a broader analysis, a multi-gene CMT panel or whole exome sequencing is available.
What is the cost of the test?
The GNB4 Gene CMTDIF NGS Genetic Test costs INR 20,000 at DNA Labs India, which includes home sample collection, NGS analysis, and a detailed clinical report.
Will I receive raw data files?
Yes, DNA Labs India is one of the few labs that provides raw data files (FASTQ and VCF) along with the clinical report for complete transparency.
How do I book this test?
You can book online by visiting our website or contacting our call center. Free home sample collection is available across India.
Is a genetic counselling session necessary?
Genetic counselling is strongly recommended before and after the test to understand the benefits, limitations, and implications of the results for you and your family.
Worried about the process? Our certified phlebotomists collect thousands of samples every month across India. The process takes under 5 minutes and is virtually painless. Questions? Message us on WhatsApp — we're here 7 days a week.

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For Hospitals & Clinics

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We serve as a reference laboratory for hospitals and clinics across India. Send samples from your facility with same-day pickup, priority processing, and results delivered through our online portal. Competitive institutional pricing available.

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