This is a second tier test and REQUIRES PERMISSION from ARUP's Genetic Counselor (800-242-2787, x2141) before ordering. Preferred initial test is the sequencing and deletion/duplication test.
- 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: Multifocal, randomly distributed, capillary malformations (CM) that may be associated with a fast-flow lesion (arteriovenous malformations [AVM] or arteriovenous fistula). Fast-flow lesions in the skin, muscle, bone, internal organs or brain can cause life-threatening complications such as bleeding, congestive heart failure, or neurological consequences. Capillary malformation-arteriovenous malformation syndrome (CM-AVM) and Parkes-Weber syndrome may be caused by RASA1 mutations.
Incidence: Estimated at 1 in 100,000.
Inheritance: Autosomal dominant; approximately one-third are de novo.
Penetrance: 90-95 percent.
Cause: Pathogenic RASA1 gene mutations.
Clinical Sensitivity: Approximately 5 percent.
Methodology: Multiplex Ligation-Dependent Probe Amplification (MLPA) to detect large RASA1 coding region deletions/duplications.
Analytical Sensitivity and Specificity: unknown and 99 percent, respectively.
Limitations: 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. The breakpoints of large deletions/duplications will not be determined. Mutations in genes other than RASA1 are not evaluated. Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.
|Component Test Code*||Component Chart Name||LOINC|
|2007831||RASA1 Disorders (RASA1) DelDup Specimen|
|2007832||RASA1 Disorders (RASA1) DelDup Interp|
- Capillary Malformation-Arteriovenous Malformation Syndrome
- Parkes-Weber Syndrome
- RASA-1 deletion/duplication assay