Calreticulin (CALR) Mutation Analysis

Clinical Use

Use

The calcium-binding endoplasmic reticulin chaperone protein, calreticulin (CALR), is somatically mutated in approximately 70% of patients with JAK2-negative essential thrombocythemia (ET) and 60% to 88% of patients with JAK2-negative primary myelofibrosis (PMF). Only a minority of patients (approximately 8%) with myelodysplasia have mutations in CALR gene. CALR mutations are rarely detected in patients with de novo acute myeloid leukemia, chronic myelogenous leukemia, lymphoid leukemia, or solid tumors. CALR mutations are not detected in polycythemia and generally appear to be mutually exclusive with JAK2 mutations and MPL mutations.

Special Instructions

Not provided.

Limitations

This PCR assay is capable of detecting a mutant cell population with a sensitivity of 5 mutant cells per 100 normal cells. A negative result does not exclude the presence of a myeloproliferative disorder or other neoplastic processes.

Test Details

Methodology

PCR-based (PCR)

Biomarkers

CALR

Gene

Mutation Detection

Mutation • Categorical (e.g., Positive / Negative / Indeterminate)

LOINC Codes

Order Codes

77174-1 - CALR Exon 9 Mut Anl Bld/T

Result Codes

77174-1 - CALR Exon 9 Mut Anl Bld/T
49549-9 - Ref lab test method
75608-0 - Citation Ref Lab Test
72486-4 - Lab director name Provider

Result Turnaround Time

5-7 days

Specimen

Whole Blood

Volume

3 to 5 mL

Minimum Volume

3 mL

Container

Lavender-top (EDTA) tube, green-top (sodium heparin) tube, tan-top (K2-EDTA) tube or pink-top (K2-EDTA) tube

Collection Instructions

Ship specimen at room temperature. Specimen should arrive in the laboratory within 48 hours of collection. If specimen is to be stored prior to shipment, store at 2°C to 8°C. Indicate date and time of collection on the test request form.

Storage Instructions

Refrigerate. Stable for 72 hours at room temperature or refrigerated.

Causes for Rejection

Specimen does not meet collection criteria; frozen whole blood, marrow, or cell pellet; leaking tube; clotted blood or marrow; grossly hemolyzed specimen or otherwise visibly degraded; contamination by another specimen; specimens containing suspicious foreign material