CAPN3 Gene Mutation Analysis, Blood Spot
This test looks for changes (mutations) in the CAPN3 gene using a dried blood spot sample. CAPN3 mutations are associated with limb-girdle muscular dystrophy type 2A (calpainopathy).
["A CAPN3 gene mutation analysis on a blood spot can help identify genetic changes linked to certain forms of limb-girdle muscular dystrophy."]
Key facts at a glance
- LOINC
- 41748-5
- Short code
- CAPN3
- Synonyms
- CAPN3 gene Mut Anl Bld/T
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA (lavender-top) tube for whole blood; sterile container for tissue specimens
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- CPT
- 81404
- SNOMED
- 444648005
- Specimen volume
- 3-5 mL whole blood in EDTA tube; 5-10 mg fresh tissue or extracted DNA
- Stability
- Whole blood: stable at room temperature for 24 hours, refrigerated (2-8°C) for 7 days; tissue: stable refrigerated for 24 hours; DNA: stable at -20°C for long-term storage
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 168–720 hours
- Order
- routine
What This Test Examines
The test analyzes the CAPN3 gene, which provides instructions for making a protein called calpain-3. This protein is important for the normal function and maintenance of skeletal muscle. The test looks for genetic variants in the CAPN3 gene that may affect how the protein works.
Why a Blood Spot Is Used
A dried blood spot is a small sample of blood collected on a special filter card, often from a heel or finger prick. This collection method is convenient and can be easier to obtain than a standard blood draw, especially in certain settings. The DNA extracted from the spot is then examined for CAPN3 gene changes.
What the Results Can Mean
Results are reported as either detecting a genetic variant in CAPN3 or not detecting one. If a variant is found, it may be classified as pathogenic, likely pathogenic, uncertain significance, likely benign, or benign, depending on current evidence. A genetic counselor or clinician can interpret what the findings mean for you or your family.
Limitations to Keep in Mind
This test focuses on the CAPN3 gene and does not rule out other genetic or non-genetic causes of muscle symptoms. Some genetic changes may not be detected by the specific method used, and variants of uncertain significance may require further study. Test results should always be considered alongside clinical findings.
Reference range
No CAPN3 pathogenic mutations detected (negative for targeted mutations). Interpretation provided in conjunction with clinical findings and family history.N/A
No special patient preparation required. Genetic counseling is recommended before and after 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
CAPN3 Gene Testing
Frequently asked questions
Is this test the same as a standard blood draw for genetic testing?
Does a normal result mean I definitely do not have a muscle disorder?
Should family members be tested too?
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