Marfan syndrome was first described in 1896 by one Dr Marfan. It is no respecter of age, sex, race, or ethnic background; anyone might be affected.
Although usually described as an inherited disorder of the connective tissue, i.e. muscles and tendons, about 25% of cases occur by spontaneous mutation. The abnormal gene appears in an egg or sperm and goes on to produce an affected child of two unaffected parents. Because Marfan syndrome is an ‘autosomal dominant’ condition, someone with Marfan syndrome has a 50% chance of passing on the condition to their offspring. Of affected children, one in ten is likely to be seriously affected.
The single abnormal gene responsible for the condition is found on chromosome 15. It reduces the production of fibrillin, a very fine fibre in connective tissue. There is currently no simple blood test available which could aid diagnosis of the condition.
There follows a brief outline of the principal features of Marfan syndrome. As these details get a little technical in places, they have been translated into simpler English at the end of each paragraph.
Ocular: Subluxation or dislocation of the lens of the eye, myopia and unstable refraction, detachment of the retina, strabismus, and glaucoma.
The lens may just be tilted slightly as opposed to completely dislocated. Short-sightedness or a squint may be observed.
Dental: High arched palate, crowding of teeth.
Cardiovascular: Dilation of the ascending and sometimes descending aorta, incompetence of the aortic and mitral valves, aneurysm and dissection of the aorta. Incompetence of aortic and mitral valves.
The main artery to and from the heart may widen, causing the wall of the artery to weaken, eventually developing a small bubble like protrusion (aneurysm), or tearing of the tissue (dissection). The valves in the heart do not operate as intended: instead of closing and opening cleanly, they ‘flop about’ in operation, billowing outwards.
Skeletal: Tall thin physique, with long limbs and fingers, spinal curvature (scoliosis) with the skin sometimes showing stretch-marks along the spine, flattening of the chest (pigeon chest or funnel deformity). Armspan will usually be significantly greater than height.
In general, Marfan syndrome is diagnosed after careful physical examination, focusing on the three main body systems involved – eyes, heart, and skeleton. Certain tests, such as an echocardiogram (a diagnostic sound picture of the heart) are useful in making the diagnosis. Marfan patients should have an initial diagnostic echocardiogram which is repeated at regular intervals. \i An electrocardiogram (ECG) or chest X-ray is not adequate screening.\i0 Skeletal X-rays of the chest and back may be necessary, and a careful eye examination, using a slit lamp to detect lens dislocation, is recommended.
Prenatal diagnosis is now available for some families with this condition, especially for those families where a change in the fibrillin gene has been demonstrated.
World-wide research is most encouraging, and a diagnostic blood test should be developed within the next few years.
Management of Marfan Syndrome
People with Marfan syndrome should be treated by a physician familiar with the disorder, conversant with its effects on all body systems and able to advise on screening of the family. Genetic counselling should be given. There is no cure for this condition yet, with careful medical and surgical management, together with an appropriate lifestyle, prognosis is greatly improved and life-span lengthened.
For more information about Marfan syndrome please visit the website for the Marfan Association UK. This site includes contact information for many countries around the world and links to on-line Marfan resources. The websites for the Marfan Syndrome Support Group Ireland, the Marfans Research Foundation, which is based in Ireland, and the National Marfan Foundation (USA) are also likely to be of interest.