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Medical Q + A

Question: Is genetic testing helpful in diagnosing Marfan syndrome?

Answer: 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 in individual cases. A genetic test alone can not tell you if you do or do not have Marfan syndrome. The diagnostic criteria for Marfan syndrome was recently revised, 2010, and does place more emphasis on genetic testing then the previous criteria did. However, genetic testing is often not covered by insurance in the United States. Genetic testing can be particularly helpful in cases where a person demonstrates features of Marfan syndrome and/or a related disorder but does not fully meet the criteria, is on the borderline of having a diagnosis. Genetic testing can also be helpful when one family member has a confirmed diagnosis of Marfan syndrome and they want to have other relatives tested to determine if they have the same mutation.

Medical Q + A: Archive

Question: What is the difference between Marfan syndrome and MASS Phenotype?

Answer: MASS Phenotype is a related disorder that does not involve the eyes, but several other systems similar to Marfan syndrome.

Mitral valve prolapse (MVP) is when the mitral valve of the heart closes properly, but then flops backward allowing leakage of blood into the chamber from which it came instead of moving forward (regurgitation)
Aortic root diameter may be at the upper limits of normal for body size, but there is no progression to aneurysm or predisposition to dissection.
Skin stretch marks unrelated to weight gain (striae).
Skeletal features of Marfan syndrome (including scoliosis, chest wall deformities, and joint hypermobility).

Who is at risk?
MASS Phenotype can be inherited within families and has been shown to result from mutations in the FBN1 gene. It is autosomal dominant, which means that someone with MASS phenotype has a 50/50 chance of passing the gene along to each child.

What is the treatment for MASS Phenotype?
Like Marfan syndrome, MASS Phenotype affects different people in different ways. It is important for a person to treat their specific symptoms, regardless of the actual diagnosis.

Question: What is the difference between Marfan syndrome (MFS), Loeys-Dietz syndrome (LDS) and Vascular Ehlers-Danlos syndrome (EDS)? Please Note: There are other types of Ehlers-Danlos syndrome. The vascular type is the most similiar to Marfan syndrome but other types types also have some overlapping features.

Answer: MFS, LDS, and vascular EDS are all genetic syndromes that affect the aorta. Although these conditions have overlapping clinical features, there are important differences in their medical management, including such important issues as different monitoring requirements and different thresholds for surgery. As a result, it is essential that a person has the correct diagnosis. The guidance of a knowledgeable geneticist is key for making the correct diagnosis. Different genes are altered in each of these disorders, and therefore genetic testing is a valuable tool in arriving at the correct diagnosis. Please Note: LDS was just identified in 2005. Due to this, there are people who were diagnosed with MFS but in reality have LDS. If you have been diagnosed with MFS but have features of LDS you should speak with a doctor who is knowledgeable in both syndromes. If you have questions about your diagnosis or need help finding a doctor in your area, contact the NMF Information Resource Center at 1-800-8-MARFAN ext. 26 or email support@marfan.org.

The gene altered in MFS is FBN1. The genes altered in LDS are TGFBR1 and TGFBR2. The gene altered in vascular EDS is COL3A1. Due to this, each syndrome is distinct and while there are overlapping features each disorder is unique. The chart below details the overlapping symptoms of Marfan syndrome with other related disorders including LDS and EDS.

Marfan Related Disorders
Condition	Symptom Overlap with Marfan Syndrome	Mutation in Fibrillin-1 Gene?
Loeys-Dietz Syndrome	Aortic enlargement and dissection. Variable skeletal findings	No (TGFBR1 or TGFBR2 mutation)
Familial Aortic Aneurysm	Aortic enlargement and dissection. Variable skeletal findings	Generally not
Bicuspid Aortic Valve with Aortic Dilation	Aortic enlargement and/or dissection	Unknown
Familial Ectopia Lentis (Dislocated Lens)	Eye lens dislocation Common skeletal findings	Yes
MASS phenotype, Mitral Valve Prolapse, Myopia	Borderline aortic enlargement Skin and skeletal findings	At least sometimes
Marfanoid Habitus (Marfan Body Type)	Skeletal findings	At least sometimes
Mitral Valve Prolapse Syndrome	Mitral valve prolapse Variable skeletal findings	At least sometimes
Congenital Contractural Arachnodactyly (CCA or Beals syndrome)	Mitral valve prolapse Variable skeletal findings	No (FBN-2 mutation)
Stickler Syndrome	Myopia Retinal detachment Joint hypermobility or contracture Scoliosis Mitral Valve Prolapse	No (Collagen genes mutation)
Shprintzen-Goldberg Syndrome	Aortic enlargement Skin and skeletal findings	Rare
Ehlers-Danlos Syndrome	Skin and skeletal findings Aortic enlargement/dissection in selected types only	No (Collagen gene mutation)
Homocystinuria	Mitral Valve Prolapse Eye lens dislocation Skin and skeletal findings	No (metabolic disorder)

So what makes MFS, LDS and vascular EDS different?

Aneurysms: Aneurysms and dissections in LDS tend to be more widespread through the the arterial tree (in arteries throughout the body), as opposed to MFS, in which the aneurysms and dissections occur primarily in th aorta. Therefore, more extensive imaging is recommended for those who have, or are suspected of having, LDS. In addition to periodic echocardiograms, CT scans or MRI's with contrast of the head, neck, chest, abdomen and pelvis are recommended. Another distinction is that aortic root aneurysms in LDS tend to dissect at smaller diameters (at a smaller size) than those in mFS. Therefore, in LDS, it is generally recommended to have surgery to repair the aortic root when the aortic size is around 4cm. In contrast, the general guideline for MFS for this surgery is around 5cm.

Vascular EDS patients can rupture or dissect an artery without having an aneurysm form (enlargement of the artery). In some patients aneurysms do form. Surgical repair of the aorta or arteries can be difficult in patients with vascular EDS because the tissue is friable and sutures sometimes do not hold well. MFS and LDS patients do not have this problem when they have surgery.

Lens Dislocation: Approximately 2/3rds of those affected with MFS have lens dislocation and many require eye surgery as a result. Lens dislocation is not known to be associated with LDS or vascular EDS. Therefore, the presence or absence of this feature can assist in arriving at the correct diagnosis.

Arterial or Organ Rupture: Arriving at the correct diagnosis of vascular EDS is important because this is considered the most serious form of EDS due to the possibility of arterial or organ rupture with this condition. The EDS National Foundation advises that chest and abdominal pain in those with vascular EDS should consider it an emergency trauma situation and immediately seek examination by MRA, MRI, or CT-scans, not x-rays because they tend not to pick up a problem with an artery.

Cervical Instability: Cervical instability is unique to Loeys-Dietz syndrome. It is therefore recommended that before people with LDS have any kind of surgery they should have an x-ray of their neck to check for cervical spine instability, which can affect intubation.

For more information on Loeys-Dietz syndrome and vascular Ehlers-Danlos syndrome click here or contact the NMF Information Resource Center at 1-800-8-MARFAN ext. 26 or support@marfan.org.

Question: Is there any way to add muscle to our arms and legs so we don't look so skinny?

Answer: There is no such thing as the perfect body. Everyone has at least a couple of things about their appearance they wish they could change, whether it is height, weight, hair, color, breast size, or musculature. You are not alone if you feel frustrated or embarrassed about your body.

Certain features, such as an indented chest can be corrected through surgery. Crowdeed teeth can be corrected with orthodontics. You may be able to get contact lenses to replace thick glasses. Talk to your doctors about your options.

Some physical aspects of Marfan syndrome and related disorders are not easily changed. For some people with Marfan syndrome and related disorders, being thin in not something likely to change. Doctors do not understand why people with Marfan syndrome have so much difficulty gaining weight. There is no special diet, dietary supplement, or weight lifting program that will add desired pounds. (Note: Weight lifting is not a safe activity for people with Marfan syndrome as it puts too much strain on the heart and aorta.) Some people with Marfan syndrome do put on more weight as they get older. Due to this it's important to have healthy eating habits now even though you may not gain any weight. Being over weight when you are older can add more stress to joints and can cause other health concerns. Remember everyone wants to change something about their body.

Teen Perspective:

Use what you have to your advantage. Be proud of the way you look and embrace your so-called "flaws." It is is those flaws that make you unique. Develop a style and flair all your own. -Anonymous

Don't panic! It's not as bad as you think! It's kind of reassuring to know there's a reason why you can't build muscle or why your skeleton is weird or why you are so tall. -Clare

For a long time I felt like Marfan syndrome was a burden, hindrance that held me back, that made me stand out when I didn't want to. I came to realize that I had it completely backwards. I am different. Being different implies individuality. With Marfan syndrome came a sharp mind, determination, motivation to succeed, and most of all a differnt perspective. -Matt