Familial Adenomatous Polyposis Panel: (APC) Sequencing and Deletion/Duplication, (MUTYH) 2 Mutations
2004915
Ordering Recommendation
Preferred diagnostic and predictive testing for familial adenomatous polyposis and MUTYH-associated polyposis.
Mnemonic
FAP Panel
Methodology
Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification
Performed
Varies
Reported
Within 28 days  
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Specimen Required
Patient Preparation
  
Collect
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).  
Specimen Preparation
Transport 3 mL whole blood. (Min: 2 mL)  
Storage/Transport Temperature
Refrigerated.  
Unacceptable Conditions
  
Remarks
  
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable  
Reference Interval
   
Interpretive Data
Background Information for Familial Adenomatous Polyposis Panel: (APC) Sequencing and Deletion/Duplication, (MUTYH) 2 Mutations:

Characteristics of APC-associated Polyposis:
Familial Adenomatous Polyposis (FAP):Development of hundreds to thousands of adenomatous colonic polyps beginning in early adolescence; lifetime risk for cancer is 100 percent. Additional findings may include dental anomalies, polyps of the gastric fundus and duodenum, and congenital hypertrophy of the retinal pigment epithelium (CHRPE).
Attenuated FAP: Fewer colonic adenomatous polyps (average of 30), which are more proximally located and cancer generally occurs at a later age; lifetime risk for cancer is 70 percent.
Gardner syndrome: Multiple colonic adenomatous polyps along with osteomas, desmoid tumors, and soft tissue tumors.
Incidence:
Less than 1 percent of colorectal cancer cases.
Inheritance:
Autosomal dominant.
Penetrance:
Greater than 99 percent in untreated individuals.
Causes:
Pathogenic APCgene mutations.
Clinical Sensitivity:
Approximately 95 percent for classic FAP and less than 30 percent for attenuated FAP.
Methodology:
Bidirectional sequencing of the APC coding region and intron-exon boundaries. Multiplex ligation-dependent probe amplification (MLPA) to detect large APC coding region deletions or duplications.
Analytical Sensitivity and Specificity:
99 percent.
Limitations
: Diagnostic errors can occur due to rare sequence variations.APC regulatory region and deep intronic mutations will not be detected. Deletion/duplication breakpoints will not be determined.

Characteristics of MUTYH-associated Polyposis (MAP):
Development of colonic polyps (10-100) with the age of diagnosis occurring in the third decade or older.
Incidence:
Less than 1 percent of colorectal cancer cases.
Inheritance:
Autosomal recessive.
Penetrance:
Greater than 99 percent in untreated individuals.
Causes:
Pathogenic biallelic MUTYH gene mutations.
Clinical Sensitivity:
85 percent of MUTYH mutations in Caucasians.
Methodology:
Targeted testing for the MUTYH mutations c.494A>G(Y165C) and c.1145G>A (G382D) by PCR and bidirectional sequencing.
Analytical Sensitivity and Specificity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Mutations in the MUTYH gene, other than Y165C and G382D, are not evaluated.





See Compliance Statement C: www.aruplab.com/CS
Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test; however, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
 
Note
 
CPT Code(s)
81201, 81203, 81401
Components
Component Test Code*Component Chart NameLOINC
2004916FAP Panel Specimen 
2004917FAP Panel Interp 
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • APC-Associated Polyposis
  • Attenuated FAP
  • Gardner Syndrome
  • Turcot Syndrome