Ordering Recommendation

Preferred test to confirm diagnosis when Marfan syndrome is strongly suspected by consensus criteria.

Mnemonic
FBN1 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
Interpretive Data

Background information for Marfan Syndrome (FBN1) Sequencing and Deletion/Duplication:
Characteristics:
Aortic root dilatation/dissection, ectopia lentis, positive wrist and/or thumb sign, pectus carinatum or excavatum, hindfoot deformity, pneumothorax, dural ectasia, acetabular protrusion, scoliosis or thoracolumbar kyphosis, reduced upper/lower segment ratio and increased arm/height ratio in persons without severe scoliosis, reduced elbow extension, skin striae, myopia, mitral valve prolapse, and characteristic facial features.
Prevalence: 1 in 5,000 - 1 in 10,000.
Inheritance: Autosomal dominant.
Penetrance: 100 percent, age-dependent.
Cause: Pathogenic FBN1 gene mutations.
Clinical Sensitivity: 70-93 percent for sequencing, unknown for deletion/duplication analysis.
Methodology: Bidirectional sequencing of the entire FBN1 coding region and intron-exon boundaries. Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large FBN1 coding region deletions/duplications.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations.  Regulatory region mutations and deep intronic mutations will not be detected. Large deletions/duplications of exon 40 may or may not be detected depending on the location of breakpoints. The breakpoints of large deletions/duplications will not be determined.  Mutations in genes other than FBN1 are not evaluated.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

81408; 81479

Components
Component Test Code* Component Chart Name LOINC
2005585 Marfan Syndrome (FBN1) Seq, Del/Dup Spcm 31208-2
2005586 Marfan Syndrome (FBN1) Seq, Del/Dup Int 40471-5
* 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
  • FBN1 genetic
  • FBN1 Sequencing and Deletion/Duplication
  • FBN1 sequencing and deletion/duplication assay
Marfan Syndrome (FBN1) Sequencing and Deletion/Duplication