Abcb1c3435ctbldtql
This test detects a specific genetic variation (c.3435C>T) in the ABCB1 gene that may affect how your body processes certain medications.
{"The ABCB1 gene test identifies a genetic variation that can influence drug response","A blood sample is collected and analyzed using molecular genetics methods","Results help doctors personalize medication choices and dosages","This polymorphism affects proteins that transport drugs in the body","Results are one factor among many that healthcare providers consider"}
Key facts at a glance
- LOINC
- 72506-9
- Short code
- ABCB1 3435CT
- Synonyms
- ABCB1 c.3435C>T Bld/T Ql
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA purple-top vacutainer tube (K2-EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 18 years
- Method
- molgen
- CPT
- 81401
- SNOMED
- 22943007
- Specimen volume
- 3-5 mL of whole blood
- Stability
- Whole blood: room temperature (15-25°C) for up to 72 hours; refrigerated (2-8°C) for up to 7 days. For longer storage, isolate mononuclear cells or store as purified DNA at -20°C or -80°C.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 72–168 hours
- Order
- routine
What is this test?
The ABCB1 gene c.3435C>T test is a genetic test that looks for a specific change (called a polymorphism) in your ABCB1 gene. The ABCB1 gene provides instructions for making a protein called P-glycoprotein, which acts like a pump that helps move certain drugs and other substances in and out of cells throughout your body.
Why might I need this test?
Your doctor may recommend this test to help predict how you might respond to certain medications. The c.3435C>T variation can affect how well P-glycoprotein works, which in turn influences the absorption, distribution, and elimination of many commonly prescribed drugs. These may include some antidepressants, anti-epileptic drugs, statins (cholesterol-lowering medications), and certain pain medications.
How is the test performed?
A healthcare professional will collect a small sample of your blood from a vein in your arm. The sample is then sent to a laboratory where technicians analyze your DNA to detect whether you have the C (cytosine) or T (thymine) version of the genetic variant at position 3435 of the ABCB1 gene. You may have one of three possible results: CC, CT, or TT.
What do the results mean?
The presence of the T variant (especially the TT genotype) may be associated with reduced activity of the P-glycoprotein transporter. This can affect blood levels of certain medications. However, the clinical impact varies depending on the specific medication being considered. Your doctor will interpret your results in the context of your overall health, other medications, and specific condition being treated.
Is special preparation needed?
No special preparation is required for this test. You can eat, drink, and take your regular medications unless your doctor instructs otherwise. The test simply requires a routine blood draw.
Reference range
This is a qualitative test detecting the presence or absence of the ABCB1 c.3435C>T variant. The result is reported as homozygous wild-type (C/C), heterozygous (C/T), or homozygous variant (T/T). No traditional reference range applies as this is a genetic polymorphism detection test.N/A
No special preparation required. Patient may eat and drink normally before specimen collection. Inform the laboratory of any recent blood transfusions, as this may affect test results. Provide current medication list for clinical interpretation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Will this test tell me which medications to take?
Does having the T variant mean I will have side effects?
Do I need to fast before this test?
How long does it take to get results?
Is this test covered by insurance?
Sources
- 1
- 2
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy