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Marfan Syndrome Facts
Marfan
syndrome (MFS) was first described by the French doctor Bernard J.A. Marfan in 1896.
Tall
thin physique, disproportionately long limbs, fingers and toes, lax ankles, flat feet, spinal curvature, abnormally shaped
narrow chest (with pigeon or funnel deformity), armspan usually greater than height, joint hypermobility or contractures and
dislocations, striae (stretch marks). Dilatation of the lumbar dural sac occurs in about 75% of patients. Hernias are common.
Dilatation of ascending and sometimes descending aorta, incompetence of aortic and mitral valves, aneurysm and dissection of aorta.
Subluxation
or dislocation of lens, myopia (short sight) and unstable refraction, detachment of retina, strabismus (squint), glaucoma.
High-arched
palate, crowding of teeth.
A single abnormal (mutant) gene on Chromosome 15 causes the condition. This abnormal gene controls production of fibrillin,
a very fine fibre in connective tissue throughout the body (the “glue and scaffolding of the body”). Most of the
time this gene is inherited from a parent who is also affected. However, about 25% of the cases occur when the abnormal gene
appears in an egg or a sperm (a spontaneous “new” mutation) producing an affected child from two unaffected
parents. Marfan Syndrome is inherited as an “autosomal dominant” condition. This means that someone with Marfan
Syndrome has a 50-50 chance that each offspring will inherit the condition, regardless of sex. On average one in ten affected
children are seriously affected.
Marfan Syndrome may be difficult to diagnose because signs of the
condition vary greatly from one person to the next. Most affected people will not have all the signs and complications of
Marfan Syndrome. Diagnosis can be confirmed within a family by genetic linkage studies.
Mutations can be found in the fibrillin-1 gene in 80% of patients, assisting with screening of family members. The identification of the chromosome, gene in 1990 and the component
of connective tissue (fibrillin) in 1991, in which the mutations for the Marfan Syndrome are located, offers great promise
as a diagnostic aid. It is hoped that as a better understanding of fibrillin is gained, earlier and more accurate diagnosis
of the Marfan Syndrome will be possible. Blood tests demonstrating the abnormal gene are becoming available
for diagnosis through referral to a clinical geneticist. Prenatal diagnosis is now available for some families with
this condition, especially those families where a mutation (change) in the fibrillin gene has been demonstrated. In general, Marfan Syndrome is diagnosed after careful physical
examination, particularly focusing on the main systems involved - Eyes, Skeleton, Heart and Lungs. Certain tests, such
as an echocardiogram (a sound-wave picture of the heart) are useful in making the diagnosis.
The
most serious life-threatening problems associated with Marfan Syndrome involve the cardiovascular system. The two leaflets
of the mitral valve may billow backwards when the heart contracts, a condition called “mitral valve prolapse”.
This feature may lead to heart failure or be associated with irregularities of the heart rhythm. The
aorta (the main artery carrying blood away from the heart) is generally wider and more fragile in people with the Marfan Syndrome.
This widening is progressive and may result in leakage of the aortic valve or in the development of tears (dissection) in
the wall of the aorta. When the aorta becomes widened, medications (e.g. beta blockers, to lower blood pressure) may be prescribed,
thereby reducing strain on the aorta and regulating heart rhythm. This may be followed by surgical repair preferably when
the aortic root widens to 5 cms diameter, and before it becomes torn. Patients
with Marfan Syndrome are recognised to have a slightly increased morbidity and mortality risk associated with general anaesthesia.
Preoperative assessment should include a thorough medical examination with a chest x-ray, electrocardiogram and echocardiogram.
Any treatment must be carried out in conjunction with the patient’s cardiologist. Antibiotics
may be prescribed prior to dental, genito-urinary or other minor surgical procedures, to reduce the risk of infection (endocarditis)
in people who experience mitral valve prolapse. Lifestyle
adaptations, such as the avoidance of strenuous exercise and contact sports, are often necessary to reduce the risk of injury
to eyes, skeleton, as well as the aorta. Beta
blockers have been shown to slow the dilation of the aortic root and their use should be considered in all patients. Regular
Echocardiograms are important to monitor size and function of the heart and aorta.
Musculo-skeletal
problems are common and troublesome in Marfan Syndrome. Indeed, recognition by a rheumatologist could be the first vital step
towards diagnosis of the underlying condition. Involvement of the skeleton includes curvature of the spine (scoliosis/kyphosis/lordosis), abnormally shaped chest
(“pectus” deformity), tall stature, and loose jointedness (often causing joint pain and dislocation). Physiotherapy, pain clinics and bracing may be helpful. In certain instances, surgery is indicated. Careful monitoring
is needed, especially during childhood and adolescence. Shoe inserts may help your child. Weak ankles may require lace-up
shoes with ankle support.
People with Marfan Syndrome
are generally near-sighted (myopic). In addition, some have dislocation of the ocular lens and retinal detachment. Glasses
and/or contact lenses may be prescribed to correct visual defects. Surgery is now available, if required, for removal and
replacement of lens(es) and retachment of retinas.
Spontaneous pneumothorax (collapse
of the lungs) is thought to occur in approximately 10% of patients and requires hospital treatment.
As a member of the Marfan Association
UK you will be made aware of current medical and surgical treatments, genetic implications and latest research results, enabling
you to become an advocate for your own health management. Understanding enables you to “come
to terms” with the disorder and to concentrate on your life as a person who happens to have Marfan Syndrome rather than
as “a Marfan patient”. Marfan Syndrome is a variable disorder, affecting everyone differently. The objective should
be to achieve a clear understanding of your needs, in partnership with your doctor.
Complications
can be prevented if patients are seen on a regular basis by their various specialists. Those affected should work closely
with physicians for individual care and management. Often your Consultant requires the test results such as X-rays, ECG (Electrocardiogram)
Echocardiogram, MRI (Magnetic Resonance Imagining) CT Scan, lung function tests prior to your appointment. Check that
this is in hand! The Association would be happy to send updated Marfan information direct to your GP and Specialists. This
is often useful prior to your appointment!
In
general it is important for the patient with Marfan Syndrome to keep as fit as possible. This improves muscle tone and is
good for overall function of the heart and blood vessels, but any exercise should be appropriate to each individual’s
physical condition. Some activities are best avoided, such as long distance running and heavy lifting.
Smoking
destroys elastin, which is the very protein which is already deficient in anyone who has Marfan Syndrome. It also causes complications
in surgery and the recovery period. It is therefore best avoided. Passive smoking again creates a problem, so - if a
smoke free zone exists - it makes sense to use it!
Having
children is a very personal decision that should be made solely by prospective parents, but only after acknowledging and understanding
the potential risks, especially if the female partner is affected. Pre-pregnancy and genetic counselling should, therefore,
be undertaken before starting a family. Remember that, although there is a 50% chance that a child may inherit the Marfan
gene, there is a 50% chance that they may not! |
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