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Cell-Free DNA KRAS 12, 13, 61, 146, Blood — Mayo Clinic Lab | Casandra.ai

Casandra

Casandra Test Code MC68312Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID KRASDCPT Codes 81275, 81276

Cell-Free DNA KRAS 12, 13, 61, 146, Blood

Clinical Use

Use

The test serves as an alternative to invasive tissue biopsies for determining the mutation status of KRAS at codons 12, 13, 61, and 146. It detects molecular markers associated with response or resistance to specific therapies, particularly in colorectal cancer patients. The test evaluates cell-free DNA (cfDNA) for KRAS mutations, providing information useful for guiding treatment decisions and assessing patient eligibility for targeted therapies.

Special Instructions

Not provided.

Limitations

This test is not intended for use as a cancer screening tool. It is not clinically validated to monitor therapy response or for early tumor detection. Negative results do not rule out the presence of KRAS mutations as the assay's limit of detection is influenced by the amount of cfDNA, a variable factor. Additionally, the test cannot differentiate between somatic and germline alterations, necessitating further testing for hereditary risk evaluation.

Test Details

New York Approved

Methodology

PCR-based (Digital Droplet Polymerase Chain Reaction)

Biomarkers

KRAS

Gene

G12A

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

G12C

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

G12D

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

G12R

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

G12S

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

G12V

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

G13D

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

Q61K

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

Q61L

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

Q61R

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

Q61H

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

A146T

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

LOINC Codes

Order Codes

In Process

Result Codes

50397-9 - Mol dx interp Bld/T Ql
69047-9 - Geneticist review
48767-8 - Annotation comment Imp
31208-2 - Specimen source
18771-6 - Provider signing name
75974-6 - KRAS gene Mut Anl Bld/T

Result Turnaround Time

5-10 days

Related Documents

For more information, please review the documents below

Lab test overview

Specimen Requirements

Specimen

Whole Blood

Volume

Two 10-mL Streck Cell-Free DNA blood collection tubes

Minimum Volume

One 10 mL Streck tube

Container

Streck Cell-Free DNA blood collection kit

Collection Instructions

Blood should be collected in Streck Cell-Free DNA BCT tubes and will be processed to produce platelet-poor plasma before cfDNA isolation. Samples should be transported at ambient temperature or refrigerated at 4 degrees Celsius.

Causes for Rejection

Specimen collected in tube other than Streck Cell-Free DNA collection tube

Stability Requirements

Temperature	Period
Room Temperature	7 days
Refrigerated	7 days