Marfan syndrome (also called Marfan's syndrome) is a genetic disorder of the connective tissue. People with Marfan's tend to be unusually tall, with long limbs and long, thin fingers. It is inherited as a dominant trait. It is carried by a gene called FBN1, which encodes a connective protein called fibrillin-1. People have a pair of FBN1 genes. Because it is dominant, people who have inherited one affected FBN1 gene from either parent will have Marfan's. Marfan syndrome has a range of expressions, from mild to severe. The most serious complications are defects of the heart valves and aorta...