This genetic disorder confers a very characteristic morphology to affected individuals.
Marfan syndrome is an autosomal dominant genetic disorder that characterizes tall, thin people with disproportionately long arms, legs, and fingers.
However, the problems associated with the syndrome are many more, and include the cardiovascular, ophthalmological and skeletal systems, mainly. In this article we will see the causes of the syndrome, its most typical symptoms and the possible complications that may appear.
Marfan syndrome: general characteristics
Marfan Syndrome consists of an autosomal dominant genetic disorder, that is, only one allele is necessary on the chromosomes of one of the parents to inherit it and therefore manifest it.
This syndrome affects the elastic fibers of the body’s connective tissue , and manifests itself in the systems or organs that most contain such fibers. These systems and organs are usually the cardiovascular system, the skin, the lungs, the skeletal system, the dura, the ocular system, and the integumentary system (teguments).
In this way, and in other words, the person affected with Marfan Syndrome suffers from a defect in fibrillin; fibrillin is a glycoprotein essential for the formation of elastic fibers in connective tissue. All this causes an abnormal formation of elastic fibers, as well as a series of dysfunctions in the tissues formed by these fibers.
On the other hand, it is known that normal fibrillin inhibits the growth of long bones, and that elastic fibers control their growth through the tension they exert. Thus, in Marfan syndrome, as there is an alteration of such structures, disproportionate bone growth occurs .
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Causes
Marfan syndrome is a genetic disease. This means that it originates from an alteration or defect in the genes, and that it is also transmitted inherited through the parents.
In this case, there is a defect in the gene that allows the body to produce a protein that helps give elasticity and strength to connective tissue .
Thus, in most people with Marfan syndrome, the defective gene (actually allele) is inherited from the parent with the disorder. Each child of an affected parent has a 50% chance of inheriting the syndrome (by inheriting the defective gene).
However, in 25% of Marfan Syndrome cases, the defective gene does not come from either parent; in these cases, the mutation has appeared spontaneously, and that person will be able to transmit the syndrome to their children.
Symptoms
Symptoms of Marfan Syndrome appear at any age, and can vary greatly from one person to another. This occurs even within the same family. Some of its most important symptoms are the following.
1. Cardiovascular involvement
On the one hand, the most remarkable symptom of Marfan Syndrome is cardiovascular involvement , characterized by progressive dilation of the aorta, which is accompanied by a high risk of suffering from aortic dissection (rupture of the aorta). In addition, such dilatation may lead to aortic valve insufficiency.
On the other hand, cardiovascular disease also includes mitral regurgitation that can cause arrhythmias, heart failure, etc.
2. Skeletal involvement
This is usually the first sign of Marfan Syndrome; it can involve excessive limb length (called dolichosthenomelia) , large stature, arachnodactyly (long, thin fingers, similar to spider legs), joint hypermobility, joint hypermobility, and scoliosis (curvature of the spine).
3. Ophthalmological involvement
At the ophthalmological level, some symptoms that appear are: an ectopia of the lens (abnormal position of the lens) and axial myopia (a type of myopia that causes images to not reach the retina clearly).
4. Other symptoms
Other symptoms that may appear in Marfan Syndrome are skin signs, such as atrophic striae (lesions on the surface of the skin), risk of pneumothorax (lung collapse) and dural ectasia (widening or bulging of the dural sac that surrounds the spinal cord ).
Associated problems
In the symptoms we have already mentioned some of the problems or complications that can arise in Marfan Syndrome. On the one hand, important cardiovascular problems can appear, such as an aneurysm in the aorta, a rupture (dissection) or malformations of the valves.
In the eyes, as we have seen, problems can also appear, for example in the retina (there is a greater risk of retinal detachment or tear). In Marfan syndrome there is also an increased risk of developing glaucoma or cataracts.
At the bone or skeletal level, as we have seen, scoliosis may appear, as well as an abnormal development of the ribs (for example, the sternum protrudes or sinks into the chest). Pain in the back and feet may also appear.
Bibliographic references
- Amaral, F., Carvalho, S., Granzotti, J., Vieira, L., Pina, N., Nunes, MA (1996). Neonatal heart failure and Marfan Syndrome. Arch Bras Cardiol, 67: 355-7.
- Oliva, P., Moreno, R., Toledo, MI, Montecinos, A., & Molina, J. (2006). Marfan syndrome. Rev Méd Chile, 134: 1455-1464.
- Orphanet Inserm. (2016). Marfan syndrome. Orphanet Encyclopedia of Disability.
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.
