Juvenile Polyposis (SMAD4) Sequencing and Deletion/Duplication
2001971
Ordering Recommendation
Diagnostic testing for juvenile polyposis syndrome/ hereditary hemorrhagic telangiectasia.  Predictive testing for juvenile polyposis syndrome/ hereditary hemorrhagic telangiectasia.
Mnemonic
SMAD4 FGA
Methodology
Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification
Performed
Varies
Reported
Within 35 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 Juvenile Polyposis (SMAD4) Sequencing and Deletion/Duplication:
Characteristics of Juvenile Polyposis Syndrome (JPS):
Gastrointestinal (GI) bleeding, multiple hamartomatous polyps in the GI tract, increased risk for GI carcinoma.
Characteristics of JP/Hereditary Hemorrhagic Telangiectasia (HHT):
Recurrent nosebleeds, telangiectases (mouth, face, hands, GI tract), arteriovenous malformations (lung, brain, liver, spine) and hamartomatous polyps in the GI tract.
Incidence:
1 in 16,000 to 1 in 100,000 for JPS; unknown for JP/HHT.
Inheritance:
Autosomal dominant; de novo mutations occur in 25 percent of JPS.
Penetrance:
Suspected to be greater than 90 percent for JPS.
Cause for JPS:
Mutations in SMAD4, BMPR1A and other unknown genes.
Cause for JP/HHT
: Mutations in SMAD4.
Clinical Sensitivity
: Approximately 25 percent for JPS; unknown for JP/HHT.
Methodology
: Bidirectional sequencing of the entire SMAD4 coding region and intron-exon boundaries. Multiplex ligation-dependent probe amplification (MLPA) to detect large SMAD4 coding region deletions/duplications.
Analytical Sensitivity and Specificity
: 99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Breakpoints for large deletions/duplications will not be determined.



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS  
Note
 
CPT Code(s)
81405; 81406
Components
Component Test Code*Component Chart Name
2001973JPS (SMAD4) Seq and Del/Dup Interp
2001975SMAD4 FGA Specimen
* 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
  • SMAD4
  • SMAD4 sqeuending and deletion/duplication