Diagnostic and predictive testing for juvenile polyposis syndrome.
- 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
Characteristics: Multiple juvenile (hamartomatous) polyps in the stomach, small intestine, colon, and rectum. Risk for colon cancer is 20 percent by age 35 and 70 percent by age 60.
Incidence: 1 in 16,000 to 100,000 individuals.
Inheritance: Autosomal dominant.
Penetrance: Greater than 90 percent for polyp development.
Cause: Pathogenic BMPR1A and SMAD4 mutations.
Clinical Sensitivity: 18 percent.
Methodology: Bidirectional sequencing of the entire BMPR1A coding region and intron-exon boundaries.
Analytical Sensitivity & Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletion/duplications will not be detected. Mutations in genes other than BMPR1A are not evaluated.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2004989||JPS (BMPR1A) Sequencing Specimen|
|2004990||JPS (BMPR1A) Sequencing Interpretation|
- BMPR1A sequencing