Genetic Mutation Screening for Cystic Fibrosis-Related Genes via Whole Blood
This test checks for specific genetic mutations linked to cystic fibrosis by analyzing your blood. It helps determine if you may carry or have cystic fibrosis.
["A genetic test to identify cystic fibrosis-related gene mutations from your blood."]
Key facts at a glance
- LOINC
- 21649-9
- Short code
- CBS
- Synonyms
- CBS gene Mut Tested Bld/T
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA tube (lavender/purple top) for whole blood; sterile container for tissue specimens
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- molgen
- CPT
- 81291
- SNOMED
- 444900002
- Specimen volume
- 3-5 mL whole blood; minimum 1 mL for pediatric samples; 5-10 mg tissue for biopsy specimens
- Stability
- Whole blood: stable at room temperature for 24 hours, refrigerated (2-8°C) for 7 days, frozen at -20°C for long-term storage. DNA extracted from sample stable for years at -20°C. Tissue: stable in sterile saline or transport medium at 2-8°C for 24-48 hours; frozen at -80°C for longer storage.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 168–720 hours
- Order
- routine
What This Test Measures
The test looks for known mutations in genes commonly associated with cystic fibrosis, such as *CFTR*. These mutations can cause the disease or increase the risk of developing it. The blood sample is analyzed to detect these genetic changes, which may not always show up in standard blood tests.
How the Test Works
Whole blood is collected and processed to extract DNA. Advanced laboratory techniques, including next-generation sequencing, identify mutations in cystic fibrosis genes. Results help guide further medical evaluation if needed.
Why It Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms of cystic fibrosis (e.g., chronic lung infections, digestive issues), a family history of cystic fibrosis, or if you’re considering pregnancy and want genetic counseling.
Preparation for the Test
No special preparation is needed. You may eat or drink normally before the blood draw. The test is typically done as part of a routine visit or during a scheduled appointment.
Reference range
No mutations detected (negative for pathogenic CBS variants); reportable as specific mutations identified or wild-type for the targeted variants analyzedN/A
No special preparation required. Patient should be informed of genetic testing implications. Genetic counseling is recommended prior to and following testing. Informed consent may be required per institutional policy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Cystic Fibrosis Gene Mutation Test (Whole Blood)
Frequently asked questions
What does a positive result mean?
What if I have a family history of cystic fibrosis?
How long does it take to get results?
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 16, 2026. · Read our editorial policy