Second, as the aorta widens, a tear can develop in the inner wall and rapidly extend to the weak middle layer. Once the tear develops, the force of pumping blood can cause the middle layer to separate, resulting in an abnormal second channel through which blood can flow. This process is called dissection, and ultimately may result in aortic rupture, which is life-threatening. Cause must be considered on several levels. A gene is a fundamental unit of heredity.
Most genes occur in pairs.
When most physicians think of cause, however, they are interested in what the mutant Marfan gene does, or does not do, to produce the syndrome. Most researchers believe that the Marfan gene produces a change in one of the proteins that provided strength to connective tissue. Proteins are the major component of connective tissue, but there are dozens of different ones and undoubtedly others yet to be discovered. Because connective tissue is so complex, discovering the so-called basic biochemical defect has been elusive. Men and women of any race or ethnic group can be affected, and no group seems particularly susceptible.