The three most common structural building blocks that constitute the ‘connective tissues’ are the proteins Collagen, Fibrillin, and Elastin. They all have important functions in maintaining elasticity and strength of these tissues. In Marfan syndrome (MFS), there is not enough Fibrillin in the connective tissues.
The biology of this is more complex than it just being about the physical amount of Fibrillin present; it is also about how Fibrillin interacts with another protein called Transforming Growth Factor – Beta and how this influences normal biochemical processes in the connective tissue. When these interactions go wrong the tissues can become weak and fragile. Fibrillin is found mainly in bones, the aorta (main artery) and the eyes. Hence, these are the parts of the body most prone to complications in MFS.
The clinical features of MFS vary considerably from person to person, with many people having only mild features. Everyone with MFS is born with the condition, but it may not be obvious before the teenage years (during the growth spurt). To add to the complexity some of the complications may not arise for many years, if indeed they arise at all. Every case has to be managed at an individual level.
If you click HERE you will be taken to the The Marfan Foundation website where there further information regarding Marfan syndrome.
A clinical overview
There are many features and a number of related symptoms found in MFS. These include:
Abnormalities of the skeleton and joints,
Defects of the heart and aorta that may be life-threatening,
Problems with the eyes,
Long term breathing issues, or sudden collapse of the lung,
Neurological problems in the legs, and
Stretch marks throughout the body, like those seen in EDS.
A diagnosis of MFS requires that very specific things are present. These include heart and blood vessel problems, and / or eye lens problems.
The musculoskeletal, lung, and skin signs and symptoms are important clues that might suggest the diagnosis of MFS, but alone they are not enough to make a diagnosis. An identifiable genetic abnormality may or may not be present.
In 2010 experts in the field of MFS from around the world published a revision of the criteria for diagnosing the condition. This is called the Revised Ghent Nosology. A web link and academic reference is provided at the end of this article.
A doctor must consider all these things before making a diagnosis of MFS and considering treatment, and will need to undertake several tests as well as record a detailed medical history and physical examination.
There is no cure for MFS. Treatment is based on managing the symptoms and reducing the risk of developing complications. Less than 50 years ago some individuals with MFS died in their 30s-40s, and mainly because of complications in their heart and aorta (see later). Now, medical treatments are so much better at preventing such problems, and surgical treatments at correcting such problems, that people with MFS have a far better quality of life and live to beyond their 70s.
Because of its complexity individuals with MFS may require a multi-disciplinary team to manage their care. This team might include the GP, Cardiologist, Ophthalmologist, Geneticist, Rheumatologist and/or Orthopaedic Surgeon, and allied health professionals such as a Physiotherapist and Occupational Therapist.
Joints, Bones and the Marfanoid habitus
A person with MFS typically has very distinct physical features. They are usually:
disproportionately long limbed and long-fingered/toed, and
flexible in their joints.
The assessing clinician must measure the arm span, leg and torso length, and hand and foot length, and compare these to the individuals’ height. They will be looking for very specific disproportionate measurements that define the Marfanoid Habitus.
As well as this there may be:
a scoliosis (curvature of the spine),
abnormal shape to the sternum (breast bone) with protrusion or indentation,
a small jaw with over-crowding of the teeth,
a high arch palate (roof of the mouth),
flat feet, and
early onset of osteoarthritis (wear and tear), particularly at the hips that may also have been stiff because the hip joint sockets are particularly deep.
These findings together are termed the marfanoid habitus. These typically appear during the late-childhood / early teenage growth phase, but may arise sooner. They do not all need to be present to use the term marfanoid habitus.
But, it is very important to understand that the vast majority of people with a marfanoid habitus do not have MFS. Also, the presence of the marfanoid habitus is not enough on its own to make a diagnosis of MFS.
For example, a marfanoid habitus is common in people who have hEDS, JHS, and HSD, but one does not see the vascular, eye, lung, or nerve complications described below in these patients.
However, to add to the complexity for the clinician, a marfanoid habitus alongside certain eye and heart complications can also be a feature of very rare conditions that may be mistaken for MFS. These are beyond the scope of this article but must always be considered by the clinician undertaking an assessment.
Symptoms and tests
The main symptoms that might arise are joint pain (e.g. back or hip pain) recurring soft tissue (tendon) injuries (e.g. at the shoulder or foot), fatigue (usually from the pain and it also disturbing sleep), and difficulty with ‘over-bite’ at the jaw or over-crowding of the teeth.
The jaw and tooth problems might also cause difficulty with speech – forming / mouthing words.
Scoliosis and/or indentation of the breastbone may also lead to breathing difficulties because of changes in shape of the chest.
Tests are most likely to include blood tests to exclude cause of fatigue or other types of arthritic condition, and imaging (e.g., x-rays, MRI, ultrasound) looking for evidence of damage to joints and soft tissue, the severity of a scoliosis or rib cage issue, or problems with the jaw/teeth.
The management of pain, fatigue, joint injuries, and joint wear and tear is no different from any other rheumatic condition in that clinicians may recommend any of the common types of treatment such as painkillers, local steroid injections, therapies such as physiotherapy and occupational therapy, and pain management programmes etc.
Where one might consider adapting treatment however would be if there was a need to be cautious in treating hypermobile joints, or where there is also a heart condition (see below) or severe scoliosis.
Sometimes there is a need for psychological support, with advice from a clinical psychologist. This may help manage the diagnosis and deal with certain symptoms and complications. There might also be issues of low self-esteem, for example a difficulty coping with ones’ appearance as the marfanoid habitus becomes apparent during teenage growth.
In general there would be no reason to avoid day-to-day activities and sport etc. However, if there are problems with the spine and joints, or with the heart then a doctor is likely to advise avoiding contact sports, heavy lifting, and high impact aerobic activities such as distance running.
If there is a mild curvature this should be monitored annually through to adulthood and then approximately every 2-5 years depending on how much it has changed (if at all) and how quickly.
Advice is very dependent on the individual situation. Exercising correctly to retain posture and core strength applies to all. In some cases a back brace may be recommended in a child while they are still growing.
In more severe cases of scoliosis (typically greater than 50 degrees curvature), surgery is usually needed. This would require an expert assessment and explanation of the procedure and the risks and benefit by a specialist spinal orthopaedic surgeon.
Correction of the breastbone and ribs:
Rarely, the sternum (breastbone) and chest wall can be so severely indented that it presses on the lungs and heart and affects breathing. Surgery may be required to relieve pressure on these organs. As with scoliosis, this requires expert opinion, and typically that of a combined cardiothoracic and orthopaedic surgical team.
Marfan syndrome can affect vision in several ways. About half of people with MFS develop an eye problem. The most well known of the problems is the tendency for the eye lens to slip (dislocate) out of place because of weakened connective tissues that hold it in position.
Other problems include:
astigmatism (abnormal curvature of either the lens or the front of the eye (the cornea)),
tear of the retina (the light-sensitive nerve layer at the back of the eye)
glaucoma (increased pressure inside the eye that damages the eye and the optic nerve), and
cataract (loss of transparency of the lens).
Symptoms and management
The symptoms are various disturbances of vision, including blurring, or a halo of light, or dark patches in the line of sight. There may be pain in the eyes. If there are any concerns it is important to get the eyesight checked by an optometrist first who will ask for the help of an ophthalmologist depending on the type of problem.
If there is a sudden loss or partial loss of vision this should be managed as an emergency and urgently checked by an Emergency Department Ophthalmologist.
Eye problems in MFS can lead to permanent loss of vision. For this reason it is important that the eyes are checked for complications and (like the heart and aorta) complications are treated as early as possible to avoid or reduce long term problems.
There are a number of treatments available. Medicines can be given in the form of eye drops. Structural problems may require glasses or contact lenses, laser therapy or surgery.
Again, like surgery to the heart and aorta, laser and surgical treatments for the eye have taken ‘leaps and bounds’ in the last 20-30 years in improving outcomes in MFS.
Lung problems in MFS are not common and not a major feature of the condition. However there are a couple of issues that can arise. The first has been raised in part in the section on scoliosis and breastbone. Changes in the shape of the chest wall can lead to difficulties with breathing.
Sometimes the actual tissues in the lungs do not function correctly because of dilation of the connective tissue walls (e.g. emphysema and bronchiectasis), or underdevelopment (hypoplasia) or constriction (fibrosis).
Perhaps the most well known of the complications is the sudden collapse of a lobe of a lung or even of the whole of one lung. The individual suddenly becomes short of breath, maybe even blue around the lips, and has pain on that side of the chest. This is called a pneumothorax – air gets trapped in the chest between the inside lining of the chest wall and the outside lining of the lung. This is an emergency needing immediate medical attention to remove the trapped air.
Heart and Blood vessels
Vascular problems tend to arise primarily in the heart and the aorta (the main artery taking blood from the heart, through the chest, and out to the body through the abdomen).
These are among the most serious concerns in MFS – because they can be life-threatening.
The key thing to appreciate though is that vascular problems in MFS tend to develop with age; they are often not present or do not cause any symptoms when younger. This is the reason why people with MFS should be screened for vascular problems and also undergo regular monitoring.
In MFS the wall of the aorta may be weak. It may balloon out or dilate to form an aneurysm that may then rupture causing serious or fatal internal bleeding.
In the heart there four valves that are ‘gates’ between the four heart chambers and major blood vessels. The two most often affected in MFS are the Mitral valve (that normally stops backpressure and blood flow back from the heart toward the lungs) and the Aortic valve (that normally stops backpressure and blood flowing back from the aorta to the heart). If these valves are weakened they ‘prolapse’, the heart has to work harder to be effective, heart muscle weakens, the chambers dilate, and the heart becomes less efficient as a pump.
Symptoms and tests
An aneurysm may be ‘silent’ until it tears or ruptures. Before this level of severity though an individual may experience chest, back or abdominal pains as the aneurysm develops.
A clinician might find unequal pulses between the arms and legs, or weak pulses and cold extremities. They may also be able to feel a dilated blood vessel in the abdomen.
A weakened heart might present with shortness of breath, chest pain, a fast heart rate.
Using a stethoscope the clinician can hear abnormal sounds of blood flowing through the valves, and fluid in the lungs because of a backpressure from the heart. They may also find complex changes in the character of the pulse and blood pressure that would lead them to be suspicious of heart valve problems.
The key investigation is echocardiography, an ultrasound technique that demonstrates the shape and functioning of the heart and aorta. There are very specific dimensional changes to the heart and aorta that have to be recorded in order to make a diagnosis of MFS. These changes are also looked for when monitoring and assessing the effectiveness of treatments, and the severity of them is used to decide if surgery.
Echocardiography might be undertaken every 6-12 months for the first few years depending on whether a problem has been identified or not. This might then change to every 2-5 years of regular monitoring, again dependent on whether anything abnormal was found in the first place and how much (if at all) the abnormality has changed over time.
In pregnancy an individual with MFS should have an echocardiogram roughly every 8-10 weeks throughout the pregnancy, and approximately 10 weeks after, before returning to their previous monitoring plan.
It is important to be aware of the common causes of heart and vascular disease that occur in the general population and to avoid these as best as possible. This includes regular checking and the control of blood pressure, and maintaining a healthy lifestyle and body-weight avoiding obesity, high cholesterol, gout and diabetes. These are all things a GP can advise one over.
Beta-blockers are often prescribed to reduce damage to the heart and aorta by controlling blood pressure, slowing down the heart rate, and decreasing the amount of force or work the heart muscle has to undertake during each heartbeat.
Studies have shown that Angiotensin Receptor Blockers (or ARBs) can reduce the risk of dilation of the aorta. There are several clinical trials currently being undertaken to determine whether ARBs may be as effective or more effective than Beta-blockers.
Heart valve surgery may be required to reduce the risk of developing life-threatening complications if the heart valves are very weak. The most common of these procedures is an aortic valve replacement and surgery to repair the first part of the aorta (the aortic ‘root’). Surgery may also be needed to repair an aneurysm.
Treatment to reduce the risk of heart and aortic complications, and surgery to correct valve prolapse and aneurysms has had a major impact on improving the lives of MFS patients.
A thin layer of tissue called the Dura lines the brain and spinal cord. Although not a very common finding, in MFS the Dura may be weakened and expand. This is called 'dural ectasia', and most often arises in the lower back. As it expands it presses on nerves. This causes back pain and numbness or pain in the legs.
Occasionally this problem can arise at the top of the neck and around the brain and give rise to headaches.
The best way to investigate this is with MRI. If it is present it may require an operation to relief the pressure on the nerves.
Genetics and Inheritance
Marfan syndrome is relatively rare, affecting about 1 in every 4000-5000 people. There is usually a family history of the condition affecting at least one parent. However about 1 in 4 cases may be the first in the family. This is because a new (‘spontaneous’) gene defect has occurred during the earliest stages of that persons’ embryonic development.
The condition has an ‘autosomal dominant’ pattern of inheritance, which means that a parent with MFS has a 50:50 chance of passing on the faulty gene to each of their children.
Although there is a gene test that can help support the diagnosis there are two very important things to be aware of:
The finding of a defective gene does not give any indication as to how serious the condition might be. This is because ‘expression’ of the gene varies between individuals, even in the same family. Offspring may only have very mild problems and symptoms, even if a parent has a lot of problems.
A negative test does not completely rule out concern. This is because there are so many gene defects that the relevant one may be so rare or brand new that it cannot be found using the tests undertaken. In most cases a diagnosis of MFS will be based on a detailed physical examination and assessment of the medical and family history.
Dr Alan Hakim MA FRCP
Consultant Rheumatologist and Physician, Barts Health NHS Trust, London
Written June 2013, reviewed April 2021, Planned Date of Review April 2024