CALR (Calreticulin) Exon 9 Mutation Analysis by PCR
Also known as: CALR
Use
This test is utilized for diagnostic and prognostic information in patients with myeloproliferative neoplasms (MPNs) when JAK2 testing is negative. Insertion/deletion mutations in exon 9 of the CALR gene result in a frameshift and are commonly found in cases of MPNs, essential thrombocythemia (ET), and primary myelofibrosis (PMF) lacking JAK2 V617F mutations. The test is particularly valuable in cases where standard markers are not detected, providing a pathway to diagnosis and tailored treatment management.
Special Instructions
The test is specifically useful in contexts where JAK2 is negative, and careful specimen handling is necessary. Whole blood or bone marrow collected in EDTA tubes must be refrigerated and transported accordingly to maintain sample integrity.
Limitations
The test does not detect mutations in other regions of the CALR gene or mutations in other genes. It has a limit of detection of 5% mutant alleles for type 1 or 2-like variants and common noncanonical variants. The 1-bp deletion variant in Exon 9 cannot be detected or reported due to methodological limitations. Results should be interpreted in the broader clinical context and should not solely be used for a diagnosis of malignancy.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 35474-6
- 31208-2
Result Turnaround Time
2-9 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
5 mL
Minimum Volume
1 mL
Container
Lavender (EDTA) tube
Collection Instructions
Do not freeze. Transport 5 mL whole blood.
Storage Instructions
Refrigerated
Causes for Rejection
Plasma, serum, FFPE tissue blocks/slides, or frozen tissue. Specimens collected in anticoagulants other than EDTA. Clotted or grossly hemolyzed specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |
| Frozen | Unacceptable |
Other tests from different labs that may be relevant