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Test ID FBN1B FBN1 Full Gene Sequence, Varies

Useful For

Aiding in the diagnosis of:

-FBN1-associated Marfan syndrome

-Autosomal dominant ectopia lentis

-Isolated ascending aortic aneurysm and dissection

-Isolated skeletal features of Marfan syndrome

-MASS phenotype (mitral valve prolapse, aortic diameter increased, stretch marks, skeletal features of MFS)-Shprintzen-Goldberg syndrome

-Autosomal dominant Weill-Marchesani syndrome

Genetics Test Information

Pathogenic FBN1 variants are most commonly associated with Marfan syndrome (MFS) but have also been reported in other rare phenotypes with variable overlap with classic MFS.


Approximately 25% to 33% of individuals with a pathogenic FBN1 variant have no family history of disease due to the variant being de novo.


Genetic testing for pathogenic FBN1 variants aids in the diagnosis of FBN1-associated MFS and other FBN1-associated conditions. Confirmation of 1 of these conditions allows for proper treatment, management, and genetic counseling.


Prior Authorization is available for this assay.


This test uses next-generation sequencing (NGS) to evaluate for the presence of FBN1 variants associated with Marfan syndrome (MFS) or other FBN1-associated conditions. Additionally, NGS is used to test for the presence of large deletions and duplications.

Method Name

Sequence Capture and Targeted Next-Generation Sequencing

Reporting Name

FBN1 Full Gene Sequence

Specimen Type


Ordering Guidance

In cases where there are hallmark features of Marfan syndrome, in particular the combination of ectopia lentis and aortic aneurysm or dissection in a patient or their family, FBN1 analysis (this assay) may be an appropriate first step in testing. In cases with more nonspecific features, such as isolated ascending aortic aneurysm or isolated skeletal features of Marfan syndrome, MFRGP / Marfan Syndrome and Related Disorders Multi-Gene Panel, Varies may be the more appropriate test to choose. Professional clinical judgment should be used by the ordering clinician. A genetic consultation may be helpful in determining the appropriate testing strategy for your patient.


Targeted testing for familial variants (also called site-specific or known mutations testing) is available for this gene. See FMTT / Familial Mutation, Targeted Testing, Varies.

Shipping Instructions

Specimen preferred to arrive within 96 hours of collection.

Necessary Information

1. Marfan and Related Disorders Patient Information (T636) is strongly recommended, but not required, to be filled out and sent with the specimen. This information aids in providing a more thorough interpretation of test results. Ordering providers are strongly encouraged to complete the form and send it with the specimen.

2. Include physician name and phone number with specimen.

3. Prior Authorization is available for this test. Submit the required form with the specimen.

Specimen Required

Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.


Submit only 1 of the following specimens:


Specimen Type: Whole blood

Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube. Do not aliquot.

Specimen Stability Information: Ambient (preferred) 4 days/Refrigerated 14 days


Specimen Type: Extracted DNA

Container/Tube: 2 mL screw top tube

Specimen Volume: 100 mcL (microliters)

Collection Instructions:

1. The preferred volume is 100 mcL at a concentration of 250 ng/mcL.

2. Include concentration and volume on tube.

Specimen Stability Information: Frozen (preferred)/Ambient/Refrigerated

Specimen Minimum Volume

Whole blood: 1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Reference Values

An interpretive report will be provided.

Day(s) Performed


Report Available

2 to 4 weeks after prior authorization is approved

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
FBN1B FBN1 Full Gene Sequence 77114-7


Result ID Test Result Name Result LOINC Value
37289 Result Summary 50397-9
37290 Result Details 82939-0
37291 Interpretation 69047-9
37292 Additional Information 48767-8
37293 Method 85069-3
37294 Disclaimer 62364-5
37295 Reviewed By 18771-6

NY State Approved



1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

2. FBN1, Full Gene Sequence Prior Authorization Ordering Instructions

3. Marfan and Related Disorders Patient Information (T636) is recommended.

4. If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen.

Prior Authorization

Insurance preauthorization is available for this testing; forms are available.


Patient financial assistance may be available to those who qualify. Patients who receive a bill from Mayo Clinic Laboratories will receive information on eligibility and how to apply.