EGFR Exon 19 Deletion Mutation Test, Whole Blood — Qualitative
A blood-based genetic test that looks for a deletion affecting exon 19 of the EGFR gene, which can occur in some lung cancers.
["This test checks blood for a specific EGFR gene change that may influence treatment choices for lung cancer."]
Key facts at a glance
- LOINC
- 55764-5
- Short code
- EGFR exon 19 Del Bld/T Ql
- Synonyms
- EGFR exon 19 Del Bld/T Ql
- Category
- kidney
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 90
- Ref high
- 120
- Critical range
- 15 N/A – —
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- CPT
- 82565
- SNOMED
- 247997009
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test examines DNA from a whole-blood sample for a deletion in exon 19 of the EGFR gene. EGFR is a gene that can be altered in certain cancers, especially lung cancer.
Why might I need this test?
A blood test may be used to look for a clinically important EGFR mutation when lung cancer is suspected or has been diagnosed. Finding this mutation can help guide decisions about targeted treatment and may lead to confirmation with a tumor-tissue or other cancer-fluid test.
How is the test performed?
A blood sample is collected, and its DNA is analyzed using laboratory methods designed to detect the EGFR exon 19 deletion. This is a qualitative test, meaning it reports whether the mutation was detected.
How do I prepare for the test?
Special preparation is usually not required. Recent blood transfusions or certain medical treatments may affect results, so tell your healthcare professional and laboratory if you have received a transfusion or are receiving treatment.
Reference range
Normal: >90 mL/min/1.73m²N/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive result means the EGFR exon 19 deletion was detected in the blood sample. This finding may be relevant when considering targeted cancer therapy. A negative result does not completely rule out the mutation because blood tests can miss low levels of tumor DNA, so additional testing may be needed.
Short name
EGFR exon 19 deletion test
Frequently asked questions
Does this test diagnose lung cancer?
Can I have this test instead of a biopsy?
What if the test result is positive?
Sources
- 1
- 2Lab Tests OnlineSource
- 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 17, 2026. · Read our editorial policy