Laboratory Test Information Guide

Details for Colon Cancer (Proband)

Test Name: Colon Cancer (Proband)
Alternate Name(s):  
Laboratory: Molecular Diagnostics
Specimen Type: Whole Blood-3 x 4 mL Lavender EDTA top Vacutainer tube
Collection Information: Blood samples must be maintained at room temperature.
Test Schedule: As Required
Monday - Friday
0800 - 1600 h
Turnaround time from when specimen
is received in testing laboratory:
3 months
Reference Range: See report
Effective Date:  
Revised Date: 2016-03-21
Critical Value: N/A
Interpretive Comments: Hereditary nonpolyposis colorectal cancer (HNPCC), or Lynch syndrome, is the most common form of hereditary colorectal cancer (CRC). HNPCC is an autosomal dominant condition in which affected individuals develop colorectal cancer or extracolonic cancers, most commonly endometrial cancer, at an early age1. Three of the DNA mismatch-repair genes that have been found to be most commonly involved in this condition are hMLH1, hMSH2 and hMSH6. Mutations in these genes are associated with a high lifetime risk of colon cancer (50-80% by age 65yrs), a 60% lifetime risk for endometrial cancer, as well as a 12% risk for ovarian cancer2. Analysis of tumour tissue in affected individuals, by a combination of immuno-histochemical staining for the hMLH1, hMSH2 or hMSH6 proteins, together with the assessment of microsatellite instability in tumour tissue DNA can often be used to confirm the HNPCC syndrome. D-causing mutations in either of these three genes be screened for direct DNA sequencing of the PCR-amplified coding exons of the affected gene(s).
1. Lynch HT, Lynch JF .Semin Surg Oncol. (2000) Jun;18(4):305-13.
Aarnio et al., Int. J. Cancer (1999) ;81:214-218.
Special Processing:  
Comments: LMS Codes:

For more information click on:
Molecular Diagnostic Laboratory.
Method of Analysis: Microsatelite Instability analysis (MSI)
Multiplex Ligation-dependent Probe Amplification (MLPA)
Direct sequence analysis of the entire coding region
Critical Information Required: Restricted to cancer genetics only.
Pedigree required.
Storage & Shipment: Must be received in testing laboratory within 48 hours of collection, shipped at room temperature by courier/overnight delivery.
System Codes: 
Referred To:  

Questions? Comments? Contact Laura Gopaul