Sorted By Test Name - Mayo Medical Laboratories

BRAZ
82899
MLH1 promoter hypermethylation are almost certainly sporadic, whereas tumors that show neither are
most often caused by an inherited mutation. Although testing for the BRAF V600E mutation and MLH1
promoter hypermethylation are best interpreted together, they are also available separately to
accommodate various clinical situations and tumor types. These tests can provide helpful diagnostic
information when evaluating an individual suspected of having HNPCC/Lynch syndrome, especially
when testing is performed in conjunction with HNPCC/17073 Hereditary Nonpolyposis Colorectal
Cancer (HNPCC) Screen, which includes MSI and IHC studies. It should be noted that these tests are not
genetic tests, but rather stratify the risk of having an inherited cancer predisposition and identify patients
who might benefit from subsequent genetic testing. See Hereditary Nonpolyposis Colorectal Cancer
Testing Algorithm in Special Instructions. Also, see Hereditary Colorectal Cancer: Hereditary
Nonpolyposis Colon Cancer (November 2005, Communique') in Publications. Assessment for the BRAF
V600E mutation has alternative clinical utilities. BRAF is part of the epidermal growth factor receptor
(EGFR) signaling cascade, which plays a role in cell proliferation. Dysregulation of this pathway is a key
factor in tumor progression. Targeted therapies directed to components of this pathway have demonstrated
some success (increased progression-free and overall survival) in treating patients with certain tumors.
Effectiveness of these therapies, however, depends in part on the mutation status of the pathway
components.
Useful For: As an adjunct to HNPCC/17073 Hereditary Nonpolyposis Colorectal Cancer (HNPCC)
Screen, when colon tumor demonstrates microsatellite instability (MSI-H) and loss of MLH1 protein
expression, to help distinguish a somatic versus germline event prior to performing expensive germline
testing As an adjunct to negative MLH1 germline testing in cases where colon tumor demonstrates MSI-H
and loss of MLH1 protein expression Note: Mayo's preferred screening test (MLBRF/87931 MLH1
Hypermethylation and BRAF Mutation Analyses) includes both MLH1 promoter hypermethylation and
BRAF V600E testing. To identify colon tumors with a previously negative KRAS mutation analysis result
that may respond to EGFR-targeted therapies. To identify melanoma tumors that may respond to
anti-BRAF targeted therapies. Note, this is a laboratory developed test and has not been FDA-approved
for this purpose.
Interpretation: An interpretive report will be provided.
Reference Values:
An interpretative report will be provided.
Clinical References: 1. Cunningham JM, Kim CY, Christensen ER, et al: The frequency of
hereditary defective mismatch repair in a prospective series of unselected colorectal carcinomas. Am J
Hum Genet 2001;69:780-790 2. Wang L, Cunningham JM, Winters JL, et al: BRAF mutations in colon
cancer are not likely attributable to defective DNA mismatch repair. Cancer Res 2003; 63:5209-5212 3.
Domingo E, Laiho P, Ollikainen M, et al: BRAF screening as a low-cost effective strategy for simplifying
HNPCC genetic testing. J Med Genet 2004;41:664-668 4. Di Nicolantonio F, Martini M, Molinari F, et al:
Wild-type BRAF is required for response to Panitumumab or Cetuximab in metastatic colorectal cancer. J
Clin Oncol 2008; 26:5705-5712. 5. Flaherty KT, Puzanov I, Kim KB, et al: Inhibition of mutated,
activated BRAF in metastatic melanoma. N Engl J Med 2010;363(9):809-819
Brazil Nut, IgE
Clinical Information: Clinical manifestations of immediate hypersensitivity (allergic) diseases are
caused by the release of proinflammatory mediators (histamine, leukotrienes, and prostaglandins) from
immunoglobulin E (IgE)-sensitized effector cells (mast cells and basophils) when cell-bound IgE
antibodies interact with allergen. In vitro serum testing for IgE antibodies provides an indication of the
immune response to allergen(s) that may be associated with allergic disease. The allergens chosen for
testing often depend upon the age of the patient, history of allergen exposure, season of the year, and
clinical manifestations. In individuals predisposed to develop allergic disease(s), the sequence of
sensitization and clinical manifestations proceed as follows: eczema and respiratory disease (rhinitis and
bronchospasm) in infants and children less than 5 years due to food sensitivity (milk, egg, soy, and wheat
proteins) followed by respiratory disease (rhinitis and asthma) in older children and adults due to
sensitivity to inhalant allergens (dust mite, mold, and pollen inhalants).
Current as of January 4, 2013 7:15 pm CST 800-533-1710 or 507-266-5700 or MayoMedicalLaboratories.com Page 292