Ordering Recommendation

Preferred DNA test for RASA1-related disorders. Confirm diagnosis in individuals with findings suggestive of capillary malformation-arteriovenous malformation (CM-AVM) syndrome or Parkes Weber syndrome (PKWS).

Mnemonic
RASA1 FGA
Methodology

Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Performed

Varies

Reported

28-35 days

New York DOH Approval Status
This test is New York DOH approved.
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

By report

Interpretive Data

Background Information for RASA1-Related Disorders (RASA1) Sequencing and Deletion/Duplication:
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 70 percent.
Methodology:
Bidirectional sequencing of all coding regions and intron-exon boundaries of the RASA1 gene; Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large RASA1 deletions/duplications.
Analytical Specificity and Sensitivity:
99 percent.
Limitations
: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations and deep intronic mutations will not be detected. The breakpoints of large deletions/duplications will not be determined.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

81479

Components
Component Test Code* Component Chart Name LOINC
2007853 RASA1 Seq, Del/Dup Specimen
2007854 RASA1 Seq, Del/Dup 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
  • Capillary Malformation-Arteriovenous Malformation Syndrome
  • Parkes-Weber Syndrome
  • RASA1 sequencing and deletion/duplication assay
RASA1-Related Disorders (RASA1) Sequencing and Deletion/Duplication