What happens in Marfan syndrome, exactly?

What is it?

Marfan syndrome is a genetic disorder that affects connective tissue. People with it tend to be tall and thin, and have long arms, legs, fingers, and bones. They often have flexible joints and scoliosis. It is not uncommon for people with Marfan syndrome to have serious problems with their heart.

About 1 in 3000 to 10 000 individuals have Marfan syndrome. Previously the cardiovascular problems associated with it caused many sufferers to die in young adulthood, the new monitoring and treatment techniques have allowed their life expectancy to rise near that of the general population.

What causes it?

Marfan syndrome is caused by a mutated gene. The condition is dominant, which means that getting just one copy of the faulty gene from one parent is enough to be affected. About 75% of cases are thought to be inherited, while about 25% are thought to be new mutations that are only present in the child.

What happens during it?

Although the mechanisms of Marfan syndrome are not entirely understood, some fairly convincing suggestions exist.

Cells are surrounded by the extracellular matrix. This is a collection of different molecules that provides structural and biochemical support to the cells. It is also a reservoir for growth factors.

A glycoprotein called fibrillin is essential for the formation of the matrix, and in particular for the elastic fibers in it, which are abundant in ligaments and the aorta. In Marfan syndrome, the gene that codes for fibrillin is not functioning properly.

One of the jobs of fibrillin is to attach to one type of growth factor and to inhibit its function. One hypothesis about Marfan syndrome is that the lack of fibrillin allows growth factor levels to rise. This could lead to an inflammatory response where enzymes are released that slowly destroy the proteins in the extracellular matrix.

How can it be treated?

The skeletal problems associated with Marfan syndrome can cause pain as well as affect self-esteem. Measures like physiotherapy, pain medication and sometimes surgery can be taken. As the heart is particularly vulnerable, it should be regularly monitored. Beta-blockers and surgery can be useful in some cases. Marfan syndrome can also cause eye problems and living with the condition can be psychologically taxing,  which should both be addressed in treatment.

 

 

Sources: https://en.wikipedia.org/wiki/Marfan_syndrome#Pathogenesis, http://emedicine.medscape.com/article/946315-overview?pa=hQrNljqeY5J6OjLCZ4Ee5jqOkgID4sUKTQDq0lwM7Y0M8DPlH%2FrzClV8irDq0tfR43mU9jD%2B1DtnxY47OmyybA%3D%3D#a5, https://en.wikipedia.org/wiki/Extracellular_matrix#Molecular_components, http://www.nhs.uk/Conditions/Marfan-syndrome/Pages/Treatment.aspx

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