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General
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Clinical Use:
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The KRAS gene encodes a 21-kDa protein that is activated transiently as a response to extracellular stimuli or signals such as growth factors, cytokines, and hormones via cell surface receptors. Activation of the KRAS oncogene prevents regulation of these pathways and has therefore been implicated in a variety of human tumours. Approximately 30-50% of colorectal cancers (CRC) have mutant KRAS. The large majority of KRAS mutations (>90%) occur in codons 12 with an amino acid substitution from a glycine at codon 12 to a valine (p.Gly12Val) or aspartate (p.Gly12Asp). Mutations have also been described in codon 13 of exon 2, with very rare mutations also described in codon 61.
KRAS mutations are predictive of resistance to epidermal growth factor receptor (EGFR) inhibitor targeted therapy such as panitumumab (Vectibix®) and cetuximab (Erbitux®) in CRCs. Patients with tumors which express the mutated version of the KRAS gene will not respond to this therapy. There are however biological differences in the various KRAS mutations and there is a subset of CRC patients which have a glycine to aspartate amino acid substitution at codon 13 (p.Gly13Asp) that do benefit with monoclonal antibody therapy directed against EGFR. |
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Availability:
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As required. |
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Aliases/Synonyms:
| GTPase KRas, K-RAS, V-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homolog, |
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Code:
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HST |
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Handling Instructions (to laboratory):
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Contact testing laboratory for specific transport instructions. |
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Hyperlink:
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Reference Interval:
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Not Applicable
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Collection Requirements
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Container:
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Sterile Container (STERILE), |
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Sample Type:
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Fresh/Frozen Tissue; Extracted DNA |
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Minimum Collection Volume:
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N/A |
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Collection Instructions:
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Processing Requirements
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Alternate Containers:
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Processing Instructions:
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Minimum Assay Volume:
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N/A |
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Stability:
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Dependent on sample type |
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Transport Instructions (to testing laboratory):
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Contact testing laboratory for specific transport instructions. |
Testing Locations
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Performed at:
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Section
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Department
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Site
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Contact Phone
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| Molecular Pathology |
Anatomical Pathology |
QEII Medical Centre |
6457 2679 |
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Last Updated : 08-10-2020 08:01 |