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Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Gene Mutation Analysis by Allele-Specific Detection

Published: August 9, 2026Updated: August 16, 2026

This test checks for specific genetic mutations linked to cystic fibrosis (CF) by examining your DNA from a blood sample.

Quick summary

["Helps diagnose cystic fibrosis or guide treatment options based on your genetic makeup."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
42938-1
Short code
CFTR1
Synonyms
CFTR allele 1 Bld/T Ql
Category
chemistry
Sample
whole-blood
Container
EDTA (purple-top) whole blood tube for blood specimens; sterile container for tissue specimens. DNA extraction requires ACD (yellow-top) or EDTA anticoagulated specimens.
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
molgen
CPT
81220
SNOMED
397669002
Specimen volume
3-5 mL whole blood in EDTA tube; minimum 1 mL for pediatric samples. Tissue specimens: 5-10 mg in sterile saline or transport medium.
Stability
Whole blood: stable at room temperature (20-25°C) for up to 7 days, refrigerated (2-8°C) for up to 30 days. Extracted DNA: stable at 2-8°C for 1 week, or at -20°C for long-term storage (>1 year). Avoid repeated freeze-thaw cycles.
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
168–720 hours
Order
routine

Why This Test Is Done

Doctors may order this test if you have symptoms of cystic fibrosis, a family history of CF, or if you’re pregnant and the father has a known CF mutation. It’s also used in newborn screening programs in some regions.

How the Test Works

Blood is drawn to collect DNA. Special laboratory techniques identify whether certain CFTR gene mutations are present in your DNA, helping pinpoint the cause of symptoms or genetic risk.

Sample Collection and Preparation

A small blood sample is taken from your arm. The blood is processed to isolate DNA, which is then analyzed for specific mutations using advanced genetic testing methods.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about any medications you’re taking, as some may affect test results indirectly. Avoid alcohol or certain supplements for 24 hours before testing if instructed.

Reference range

Negative (no CFTR mutation allele 1 detected). A negative result does not exclude the presence of other CFTR mutations not included in the testing panel. Reference range for this qualitative assay is reported as Detected or Not Detected.N/A

Specimen: whole-blood

No special patient preparation or fasting required. Informed consent may be required for genetic testing per institutional and state regulations. Genetic counseling is recommended before and after testing. Patient should be informed of potential implications for family members and insurance.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

CFTR Gene Mutation Test

Frequently asked questions

This test is critical for confirming a cystic fibrosis diagnosis, especially in newborns or those with unexplained respiratory, digestive, or nutritional issues. It also helps determine if you’re a carrier of CF mutations, which is important for family planning.
This test can’t diagnose CF in everyone—additional tests (like sweat chloride testing) may be needed to confirm the condition. Results guide treatment plans, such as enzyme replacement therapy or lifestyle adjustments.
What does a positive result mean?
A positive result means you have one or more known cystic fibrosis mutations in your DNA. This may indicate you have CF or are a carrier. Your doctor will discuss next steps, such as sweat testing or genetic counseling.
How long does it take to get results?
Results are typically available within 2–4 weeks, depending on the lab and testing complexity. Follow-up with your healthcare provider is important to interpret results and plan next steps.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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