Familial Adenomatous Polyposis (APC) Deletion/Duplication (INACTIVE as of 05/15/17: Refer to 2004915)
Ordering Recommendation

Second-tier diagnostic or predictive test for familial adenomatous polyposis. Order if no variants were detected by APC sequencing, or concurrently with Familial Adenomatous Polyposis (APC) Sequencing (2004863), or if there is a known familial APC deletion.

Polymerase Chain Reaction/Multiplex Ligation-dependent Probe Amplification
Within 14 days
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B). 
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL) 
Storage/Transport Temperature
Unacceptable Conditions
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable 
Reference Interval
Interpretive Data
Background Information for Familial Adenomatous Polyposis (APC) Deletion/Duplication:
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 with classic FAP.
Pathogenic APC mutations.
Clinical Sensitivity: Approximately 8-12 percent for classic FAP.
Methodology: Multiplex ligation-dependent probe amplification (MLPA) to detect large APC coding region deletions and duplications.
Analytical Sensitivity and Specificity of MLPA: 99percent.
: Diagnostic errors can occur due to rare sequence variations. Single base pair substitutions, small deletions/duplications, regulatory region mutations, and deep intronic mutations will not be detected. Deletion/duplication breakpoints will not be determined. Mutations in genes other than APC will not be detected.

Compliance 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.

Component Test Code*Component Chart NameLOINC
2004921FAP (APC) Del/Dup Specimen31208-2
2004922FAP (APC) Del/Dup Interpretation20990-8
* 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.
  • APC-Associated Polyposis
  • Attenuated FAP
  • Gardner Syndrome
  • Turcot Syndrome