Which of the Following is True About Marfan Syndrome

Question

Which of the following is true about Marfan syndrome?  
A) The cause is an autosomal recessive mutation.
B) The affected gene produces a defective form of the protein actin.
C) Connective tissues comprising the heart and blood vessels are weakened.
D) One in 5,000 men are affected.
E) Those affected are often very short and have mental impairments.

Accepted Answer

Marfan syndrome is caused by a mutation in the gene that encodes fibrillin-1, which is a protein that helps form elastic fibers within connective tissue. The weakened connective tissues can affect multiple systems in the body, including the heart and blood vessels, resulting in aortic aneurysms and other cardiovascular problems. It is inherited in an autosomal dominant pattern. Some people with Marfan syndrome may be tall and thin, but height is not consistently affected, and mental impairments are not a characteristic of the condition. The estimated prevalence of Marfan syndrome is approximately 1 in 5,000 to 10,000 individuals.