GSTT1 Gene Glutathione S-transferase theta-1 defficiency NGS Genetic Test
Short Name: GSTT1 Gene NGS Test
Also known as: GSTT1 Genotyping Test, Glutathione S-transferase Theta-1 Gene Analysis, GSTT1 Null Genotype Test, GSTT1 Deletion Polymorphism Test, GSTT1 Enzyme Deficiency Genetic Test
GSTT1 Gene Glutathione S-transferase theta-1 defficiency NGS Genetic Test test available at DNA Labs India for ₹20,000. Uses Next-Generation Sequencing (NGS), PCR-based Confirmation, Bioinformatic Variant Analysis 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 receipt at the laboratory.. 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 purpose of this test is to determine the GSTT1 genotype of an individual to assess their detoxification capacity, evaluate susceptibility to environmental and occupational carcinogens, guide pharmacogenomic decision-making for medications metabolized by the GSTT1 pathway, and provide personalized risk assessment for conditions associated with GSTT1 deficiency. This test is also valuable for population screening studies and occupational health evaluations.
- Test Code
- 2023
- CPT Code
- 81479
- ICD Code
- E88.89
- 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 receipt at the laboratory.
- Fasting Required
- No
- Method
- Next-Generation Sequencing (NGS), PCR-based Confirmation, Bioinformatic Variant Analysis
Sample Collection
No special preparation or fasting is required. A pre-test genetic counseling session is recommended to discuss the clinical indication, family history, and to construct a pedigree chart of family members affected with GSTT1-related conditions. Provide complete clinical history of the patient including medications, occupational exposures, and prior genetic test results.
Method: Venipuncture
Laboratory Analysis
A standard venipuncture will be performed to collect 3-5 mL of peripheral blood into an EDTA vacutainer. Alternatively, one drop of blood on an FTA card or previously extracted DNA may be submitted. The procedure typically takes less than 10 minutes.
Report Delivery
Apply pressure to the puncture site with a cotton ball or gauze for 3-5 minutes. A small bruise may develop at the site, which typically resolves within a few days. Reports 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 receipt at the laboratory.
Patient Instructions
About This Test
Who Should Get This Test
The purpose of this test is to determine the GSTT1 genotype of an individual to assess their detoxification capacity, evaluate susceptibility to environmental and occupational carcinogens, guide pharmacogenomic decision-making for medications metabolized by the GSTT1 pathway, and provide personalized risk assessment for conditions associated with GSTT1 deficiency. This test is also valuable for population screening studies and occupational health evaluations.
How to Prepare
- No fasting is required prior to sample collection
- Maintain ambient room temperature during sample transport
- If using an FTA card, ensure the blood drop fully saturates the designated area and allow it to dry completely before packaging
- If previously extracted DNA is available, submit a minimum of 1 microgram of DNA at a concentration of at least 50 ng/µL
- Label the sample container clearly with the patient's full name, date of birth, and sample ID
- Complete the test requisition form with clinical history and genetic counseling details
Doctor's Notes
Reviewed by Dr SULOCHANA HEMCHANDRA HOLLA — MBBS, MD (Medical Genetics) · Reg. No. 8532
"GSTT1 deficiency is a clinically significant pharmacogenomic and detoxification marker. Individuals homozygous for the GSTT1 null genotype lack functional glutathione S-transferase theta-1 enzyme activity, which may impair their ability to metabolize environmental carcinogens, certain chemotherapeutic agents, and industrial chemicals. I recommend this test for patients with a family history of GSTT1-related conditions, unexplained drug sensitivities, occupational exposure to toxins, or those undergoing pharmacogenomic evaluation prior to treatment. Early identification through NGS testing allows for personalized risk assessment, lifestyle modifications, and informed clinical decision-making. A genetic counseling session before and after testing is strongly advised."
Last medically reviewed: September 7, 2026
Test Parameters & Specifications
Sample Stability
- Clotted blood sample
- Insufficient sample volume (less than 2 mL)
- Hemolyzed or severely lipemic samples
- Incorrectly labeled or unlabeled samples
- Samples received beyond stability period without prior intimation
- Samples without completed requisition form or clinical history
Understanding Your Results
Homozygous Wild-Type (GSTT1*1/GSTT1*1)
Normal detoxification capacity. No increased risk attributable to GSTT1 deficiency.
Heterozygous (GSTT1*1/GSTT1*0)
Intermediate phenotype. May have moderately reduced detoxification capacity. Clinical impact varies depending on environmental exposures and other genetic factors.
Homozygous Null (GSTT1*0/GSTT1*0)
Absent enzyme activity. Associated with increased susceptibility to environmental carcinogens, heightened sensitivity to certain drugs and chemicals, and potentially elevated risk for specific cancers. Personalized risk management and avoidance of relevant exposures is advised.
Pathogenic or Likely Pathogenic Sequence Variant Detected
May result in reduced or absent enzyme activity depending on the nature of the variant. Genetic counseling is recommended for further evaluation and risk assessment.
Variant of Uncertain Significance (VUS)
Cannot be used for clinical decision-making at this time. Re-analysis may be performed as new scientific evidence becomes available. Genetic counseling is recommended.
Consult a clinical geneticist or your referring physician if your test result shows a homozygous null genotype or if pathogenic/likely pathogenic variants are detected. Genetic counseling is recommended to understand the implications for your health, family planning, and to develop a personalized risk management plan. If you experience unexplained drug reactions, occupational health concerns, or have a family history of cancer, seek medical guidance promptly.
Limitations
- ⚠This test detects variants in the GSTT1 gene only and does not assess other glutathione S-transferase family members (e.g., GSTM1, GSTP1)
- ⚠Deep intronic regulatory variants outside the sequenced regions may not be detected
- ⚠The clinical significance of some detected variants may be uncertain (VUS)
- ⚠Results should be interpreted in the context of clinical findings and family history with guidance from a qualified genetic counselor
- ⚠This test does not measure GSTT1 enzyme activity directly; it identifies the genetic basis for potential deficiency
Risks & Considerations
- ●Mild bruising or soreness at the blood draw site
- ●Very rare risk of infection at the puncture site
- ●Psychological impact of learning about genetic predispositions; genetic counseling is recommended
- ●Potential for uncertain results (VUS) that may cause anxiety; discuss implications with your genetic counselor
Interfering Factors
- ●Recent blood transfusion within the past 4 weeks may affect DNA analysis results
- ●Bone marrow or stem cell transplant may yield donor DNA profile
- ●Degraded or insufficient DNA quality may compromise sequencing accuracy
- ●Contamination during sample collection or processing
Compare With Similar Tests
| Test | GSTT1 Gene Glutathione S-transferase theta-1 defficiency NGS Genetic Test | GSTM1 Gene Polymorphism Test | GSTP1 Gene Analysis | Comprehensive Pharmacogenomics Panel | NAT2 Gene Acetylation Test | Cancer Susceptibility Gene Panel |
|---|---|---|---|---|---|---|
| Comparison | GSTT1 Gene Glutathione S-transferase theta-1 defficiency NGS Genetic Test | Both GSTT1 and GSTM1 belong to the glutathione S-transferase superfamily and share common substrates. GSTM1 testing assesses a different isoform. Combined GSTT1 and GSTM1 genotyping provides a more comprehensive detoxification profile. | GSTP1 encodes the pi-class glutathione S-transferase. While GSTT1 is primarily hepatic, GSTP1 is widely expressed in multiple tissues including the lungs and intestines. GSTP1 analysis focuses on point mutations rather than whole-gene deletions. | A pharmacogenomics panel tests multiple genes simultaneously (including CYP450 enzymes, NAT2, and GSTs) to guide drug dosing and selection. The GSTT1 test is a focused single-gene assessment, while the panel provides a broader pharmacogenomic profile. | NAT2 assesses another phase II detoxification enzyme, N-acetyltransferase 2. While GSTT1 catalyzes glutathione conjugation, NAT2 catalyzes acetylation. Together, they provide complementary information about an individual's overall detoxification capacity. | Cancer gene panels (e.g., BRCA1/2, TP53, MLH1) assess high-penetrance cancer predisposition genes. GSTT1 deficiency represents a low-to-moderate penetrance susceptibility factor. The GSTT1 test is complementary to, not a substitute for, comprehensive cancer gene panels. |
Frequently Asked Questions
What is GSTT1 Gene Glutathione S-transferase theta-1 deficiency?
What is the GSTT1 NGS Genetic Test?
Who should consider getting the GSTT1 Gene NGS Genetic Test?
What sample is required for this genetic test?
What does a positive result (GSTT1 null genotype) mean?
Is GSTT1 deficiency hereditary?
Can GSTT1 deficiency be treated or cured?
How long does it take to get the results of the GSTT1 Gene NGS Genetic Test?
What is the cost of the GSTT1 Gene Glutathione S-transferase theta-1 Deficiency NGS Genetic Test?
Does DNA Labs India provide raw genetic data along with the report?
Is the GSTT1 Gene NGS Genetic Test painful or risky?
Is the GSTT1 Gene NGS Genetic Test covered by insurance in India?
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