What are causes of Marfan syndrome?

Marfan syndrome is an inherited genetic disorder that is caused by mutations in the FBN1 gene, which provides instructions for making a protein called fibrillin-1. This protein is involved in the formation of elastic fibers, which provide strength and flexibility to connective tissue throughout the body. Mutations in the FBN1 gene lead to the production of abnormal fibrillin-1, which results in weak and fragile connective tissue.

The specific cause of Marfan syndrome is the mutation in the FBN1 gene. There are several types of mutations that can occur, and each one can result in different symptoms and severity of the condition.

Most cases of Marfan syndrome are inherited in an autosomal dominant pattern, which means that only one copy of the affected gene is needed to cause the condition. In about 25% of cases, however, the mutation occurs spontaneously and is not inherited from either parent. This is known as a de novo mutation.

In rare cases, Marfan syndrome can also be caused by mutations in other genes, such as the TGFBR1 or TGFBR2 genes. These genes encode for proteins that are involved in the transforming growth factor beta (TGF-beta) signaling pathway, which is important for the regulation of connective tissue development. Mutations in these genes can lead to similar symptoms to those of Marfan syndrome, although they may be less severe.