Development and validation of CALR mutation testing for clinical diagnosis.

Area of Science:

• Molecular Diagnostics
• Oncology
• Genetics

Background:

• Calreticulin (CALR) mutations are key drivers in myeloproliferative neoplasms (MPNs).
• Accurate detection of CALR mutations is crucial for diagnosis and patient management.
• Existing diagnostic methods require validation for clinical utility.

Purpose of the Study:

• To validate a diagnostic assay for detecting CALR mutations in clinical samples.
• To assess the accuracy and reproducibility of fragment length analysis (FLA) for CALR mutation detection.
• To establish a reliable method for routine clinical use.

Main Methods:

• DNA extraction from bone marrow aspirates (BMAs) and peripheral blood (PB) samples.
• Polymerase chain reaction (PCR) amplification of CALR exon 9.
• Fragment length analysis (FLA) by capillary electrophoresis for mutation detection.
• Sanger sequencing for mutation confirmation.

Main Results:

• CALR mutations were detected in 14 samples from 10 patients with JAK2/MPL wild-type MPNs.
• FLA identified various deletions and insertions in CALR exon 9.
• Sanger sequencing confirmed 100% concordance with FLA.
• High reproducibility and concordance between matched PB and BMA samples were observed.

Conclusions:

• FLA of PCR amplicons by capillary electrophoresis provides a quick and accurate method for CALR mutation detection.
• The validated assay is suitable for routine clinical diagnostic testing.
• This assay facilitates the incorporation of CALR mutation testing into laboratory workflows.