Marfan syndrome - Genetics and Inheritance
Marfan Syndrome Genetics
Marfan syndrome is an inherited autosomal dominant disorder that occurs because of a defect in a gene called FBN1 (fibrillin-1) which is present on chromosome 15. It mainly affects the connective tissue of the affected individual. The mutation affects the formation of fibrillin and elastic fibers that are essential components of connective tissue. Important body structures that can be affected include the heart, blood vessels, skeleton, eyes, bones, skin, and lungs.
Autosomal dominant inheritance means that inheritance of a single copy of the defective gene is enough to cause the disorder; that gene can be inherited from a single affected parent. A child has a 50% chance of inheriting Marfan syndrome from an affected parent.
Signs and Symptoms of Marfan Syndrome
Marfan syndrome is present at birth, but symptoms may appear later in life. It mainly affects the connective tissue of the body, and the degree of symptoms may vary from patient to patient.
People with Marfan syndrome tend to be tall and have thin skeletons. Arms, legs, fingers, and toes are disproportionately long relative to the rest of the body, and bones and joints may become brittle.
Marfan syndrome may also cause the formation of defective connective tissues in the heart, blood vessels, eyes, or lungs.
In the heart the genetic disorder affects the valves and produces mitrial valve prolapse. As a result a patient will experience shortness of breath, tiredness, and palpitations.
If the eyes are affected objects can appear blurred, there’s dislocation of the lens and changes in the shape of the eye.
In blood vessels Marfan syndrome causes dilatation of the arteries, which can rupture, resulting in a life-threatening condition. Principally the aorta is affected, the main artery that supplies blood from the heart to all other parts of the body.
When the lungs are affected, bronchitis, pneumonia, and emphysema may result.
Treatment and Cure
Currently there is no cure for Marfan syndrome; symptoms are treated and lifestyle adjustments may be necessary. The outlook for patients has greatly improved as advances in medical knowledge have allowed for earlier diagnosis, identification of risk factors, and better management of the condition. It means that with early diagnosis and intervention, individuals with Marfan syndrome can experience a similar life expectancy as the average person.