Marfan syndrome : FBN1 Sequencing

Test Information

FBN1 sequencing is a molecular test used to identify variants in the gene associated with Marfan syndrome .

Turnaround Time

6 weeks

CPT Code(s)





  • FBN1

Clinical Information

Marfan syndrome is an autosomal dominant, highly variable disorder of connective tissue. Features of Marfan syndrome can include: pectus excavatum, reduced upper-to-lower segment ratio, wrist/thumb signs, scoliosis, joint hypermobility, high arched palate, ectopia lentis, dilatation or dissection of the ascending aorta, mitral valve prolapse, pneumothorax, and striae atrophicae. Specific diagnostic criteria for a clinical diagnosis of Marfan syndrome have been described.


Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.


Sanger Sequencing


Sequencing of the FBN1 gene will detect mutations in approximately 70-93% of individuals with a clinical diagnosis of Marfan syndrome.

Specimen Requirements

The preferred sample type is peripheral blood collected in an EDTA (purple top) tube - at least 2-3ml for pediatric patients and 5-6ml for adult patients. Extracted DNA, dried blood spots, and saliva are also accepted for this test. Saliva samples must be submitted in an approved saliva kit. Contact the lab to receive a saliva kit or to have one sent to your patient.

Transport Instructions

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal Testing Information

Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.

Have Questions? Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Falecia Thomas, MS, CGC

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