Although scientists have determined that Marfan syndrome (MFS) is caused by a defect in the fibrillin 1 gene on chromosome 15, there is no simple blood test that can conclusively diagnose Marfan syndrome. Therefore, diagnosis is made through a clinical evaluation.
What should you do if you suspect Marfan syndrome?
Find a doctor who knows about Marfan syndrome. The first choice of doctor to look for is a medical geneticist (a doctor who specializes in genetic conditions such as Marfan syndrome).
A second choice is a cardiologist (heart doctor). Make sure the cardiologist has treated people who have MFS.
You can find a doctor by:
- Asking your primary doctor for a referral
- Calling the doctor referral service at your local hospital
- Calling your insurance provider
- Calling the National Marfan Foundation Resource Center at 800-862-7326, ext. 26
Learn the health history of you and your family. You might want to write this down in a health history notebook with lists of: - Your past illnesses, operations, and hospitalizations
- Medications you are taking
- Reasons why you think you might have MFS
- Family members who have, or might have, MFS
- Family members who died of a heart problem
The NMF has created a Family Health History template for you to save to your computer. The U.S. Department of Health and Human Services offers an internet-based family health history tool which may also be helpful. How is Marfan syndrome diagnosed?
Marfan Syndrome Diagnostic Criteria is a list of features doctors use to diagnose (decide if someone has) Marfan syndrome. Diagnostic criteria are sometimes called “Ghent Criteria,” named after the city in Belgium where doctors decided which features to include on the list. Some of these features are easy to see. Others need special tests to find them. These common, painless tests which are part of the clinical evaluation include: - Echocardiogram
This test looks at the heart, its valves, and the aorta (vessel that carries blood from the heart). - Electrocardiogram (EKG)
This test checks your heart rate and heart rhythm. Your doctor may to do both an EKG and an echocardiogram. - Slit lamp eye exam
This test, a part of most eye exams, helps your doctor see if the lenses in your eyes are dislocated (out of place). - Other tests, such as a CT scan or MRI of the lower back
These tests can help your doctor see if you have dural ectasia, a back problem that is very common in people who have MFS.
What are the diagnostic criteria (features)?
There are both major and minor diagnostic criteria. “Major criteria” refers to features that are common in people with Marfan syndrome, but rare in others. “Minor criteria” are features that are common in many people -- those with and without Marfan syndrome.
Since Marfan syndrome affects many body systems, there are diagnostic criteria for many parts of the body (see chart below). | Body System | Major Criteria
| Minor Criteria
| | Skeletal System (Bones & Joints) | Major criteria of the skeletal system are met when a person has at least 4 of these features: - A chest that sticks out (pectus carinatum)
- A chest that sinks in so much as to need surgery (pectus excavatum).
- Arm span greater than height. This means that when your arms are stretched to the side, the distance from finger tip to finger tip is greater than your height, OR
- Reduced upper to lower segment ratio. This is when the length of your torso (from shoulders to legs) is shorter than the length of your legs.
- Positive wrist sign. This is when your thumb and little finger overlap when you grasp the other wrist.
- Positive thumb sign. This is when you put your thumb on your hand and it extends beyond the palm.
- Curvature of the spine (scoliosis) with a curve greater than 20 degrees.
- Vertebrae (spine bones) that slip over each other (spondylolisthesis).
- Flat feet (pes planus).
- Extra-deep hip sockets (where the thigh bone meets the hip). This is also called “protrusion acetabulae” and doctors find it by hip x-ray.
| - A chest that sinks in, but not so much as to need surgery.
- Very flexible joints throughout your body.
- The palate (roof) of your mouth is highly arched and the teeth are very crowded.
- Certain facial features such as: a long, thin face; deep-set eyes; receding chin; or down-slanting eyes.
| | Ocular System (eyes) | - Ectopia lentis (dislocated lens of the eye)
| - Abnormally flat cornea (as measured by keratometry)
- Increased axial length of globe (as measured by ultrasound)
- hypoplastic iris or ciliary muscle, causing decreased miosis
| | Cardiovascular System (Heart & Blood Vessels) | - The part of your aorta closest to the heart bulges out or is enlarged (ascending aortic dilation or aneurysm).
- The layers of the ascending aorta are separated and may tear (dissection of the ascending aorta).
| - A “floppy” mitral valve (mitral valve prolapse, or MVP).
- Enlarged pulmonary artery without any known cause, before age 40.
- Calcium deposits in the mitral valve, before age 40
- A part of the aorta – either in the chest (descending thoracic aorta) or stomach (abdominal aorta) – is enlarged, before age 50.
- Tearing (dissection) of the aorta in the chest or stomach, before age 50.
| | Pulmonary System (Lungs) | There are no major criteria of the pulmonary system. | - Sudden collapse of the lung for no known reason (spontaneous pneumothorax)
- Extra-large air sacs at the top of the lung (apical blebs). These are found by chest x-ray.
| | Skin | There are no major criteria of the skin.
| - Skin stretch marks, not due to pregnancy or weight gain.
- Two or more hernias (recurrent hernia).
| | Spinal Column Sac (Dura) | Swelling of the sac around the spinal column (dural ectasia). This is found with CT or MRI scans of the back. | There are no minor criteria of the spinal column sac. |
Is there a blood test (genetic test) for Marfan syndrome?
Yes, but the use of genetic testing for the diagnosis of genetic disorders can be very complicated. This is certainly true for Marfan syndrome. Input from a geneticist or genetic counselor may be necessary to achieve a full understanding of the capabilities and limitations of genetic testing for Marfan syndrome.
At this time, there is limited use for genetic testing and a comprehensive clinical evaluation remains the most effective way to make a diagnosis of Marfan syndrome.
A genetic test alone can not tell you if you do or do not have Marfan syndrome.
How do doctors use the diagnostic criteria?
To diagnose Marfan syndrome, doctors compare a person’s test results, health history, and physical examination with the diagnostic criteria. - If no one else in the family has Marfan syndrome, then doctors diagnose Marfan syndrome when a person has major criteria in at least two body systems and a minor criteria in a third.
- If a parent or sibling (brother or sister) has Marfan syndrome, then doctors diagnose Marfan syndrome when a person has a major criteria in one body system and a minor criteria in another.
It can be hard for even skilled doctors to make this diagnosis as features may be due to Marfan syndrome or happen for other reasons. Doctors who see many people with Marfan syndrome are more likely to make the correct diagnosis.
What are the possible diagnoses?
A person with Marfan features may or may not have Marfan syndrome. Here are some diagnoses that doctors can make: - Marfan syndrome
A doctor makes this diagnosis when a person has the major and minor criteria as described above. In these cases, it can be said that a person “meets” the diagnostic criteria for Marfan syndrome. - Emerging Marfan syndrome
Doctors may use this term when a child (or sometimes an adult) has just some of the diagnostic criteria for Marfan syndrome. This is likely when doctors think the child will have more features as the child grows older. - Some other genetic disorder of connective tissue
A person who does not meet the diagnostic criteria for Marfan syndrome may instead have another genetic disorder of connective tissue. These related disorders include: Ehlers-Danlos syndrome, Loeys-Dietz syndrome, MASS phenotype, familial aortic aneurysm, and Sticklers syndrome. - No specific diagnosis
This term is used when a person has Marfan features but does not meet the diagnostic criteria for any known disorder.
It is important to understand that a person can have many Marfan features, but not have Marfan syndrome. For instance, a person may have many skeletal features, but that would only count as one major criteria - that being of the skeletal system. The same person would need to have criteria in other body systems in order to be diagnosed with Marfan syndrome.
Many people with Marfan features (whether they have a diagnosis or not) need medical treatment and follow-up care. Make sure to talk with your doctor about the care that is right for you.
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