Marfan syndrome is a condition that affects the body’s connective tissue. Connective tissue holds together and provides strength and flexibility to our body’s tissues and organs. When the connective tissue does not function properly, medical problems arise which may be present in a variety of body systems, most commonly the bones, heart, and eyes.
Approximately 1 in 5,000-10,000 people have Marfan syndrome.
The most common features of Marfan syndrome are found in the eyes, heart, and bones, but other body systems may also be affected.
Eyes- A hallmark feature of Marfan syndrome is ectopia lentis or dislocation of the lens in the eye. This affects 60% of individuals with Marfan and may require a special examination with a slit lamp to detect. Myopia (nearsightedness) often affects individuals with Marfan syndrome which can progress rapidly during childhood and is easily managed with eyeglasses.
Heart- The abnormal functioning of the connective tissue makes the aorta, the major blood vessel coming off of the heart, especially susceptible to dilation (widening), tearing, or rupture. Aortic dilation can worsen over time, increasing the risk for tearing or rupture which can be life threatening. The age at which aortic dilation begins and the progression over time vary greatly from person to person. In addition, the valves of the heart are susceptible to prolapse, or slipping, causing abnormal blood flow and potentially congestive heart failure.
Bones- Marfan syndrome affects the way certain bones and joints develop. Individuals with Marfan syndrome often have long arms, legs, and fingers with especially loose, flexible joints. The ribs can also be longer than expected, pushing the chest out or in. Loose joints can lead to scoliosis (curved spine) or flat feet.
Not every individual with Marfan syndrome has the all of the features of the condition or the same level of severity of features. Other medical conditions have features that overlap with Marfan syndrome. “The revised Ghent nosology for the Marfan syndrome” is a set of criteria used by clinicians to determine which features an individual has and whether that individual has a clinical diagnosis of Marfan syndrome (PMID: 20591885).
Marfan syndrome is caused by variants in the genetic code of the FBN1 gene. It is diagnosed by applying “The revised Ghent nosology for the Marfan syndrome”, which incorporates the results of FBN1 genetic testing when available.
Marfan syndrome can be diagnosed clinically by applying the Revised Ghent Nosology. Genetic testing may contribute to the clinical diagnosis or confirm the diagnosis in an individual who already meets criteria for a clinical diagnosis of Marfan syndrome. Genetic testing may also help identify other family member who have Marfan syndrome, once the genetic variant is identified in an individual.
The features of Marfan syndrome are best treated by a coordinated, multidisciplinary team of clinicians based on their presence and severity in an individual. For example, a cardiologist will examine, monitor, and recommend treatment regarding the status of an individual’s aorta and an ophthalmologist will do the same for the individual’s eyes and vision.
Genetic testing can contribute to confirming that an individual indeed has Marfan syndrome, but the results of a genetic test will not be able to determine what features will be present in an individual nor how severe those features will be.
If the genetic cause of Marfan syndrome is identified in an individual, genetic testing for other family members may be indicated to assess their risk for the condition and the need for possibly life-saving treatment. Family testing is important because relatives may be at risk regardless of whether or not they are experiencing any symptoms.
Your physician will assist you in identifying and arranging for the appropriate genetic test(s). If you have specific questions or concerns about the testing, your physician may refer you to a genetic counselor to discuss further. Once you are ready to proceed with genetic testing, you will need to submit either a blood or saliva sample.