Yes, it can be inherited, but it can also occur without any family history at all.

Marfan syndrome follows what’s called an autosomal dominant pattern of inheritance. In simple terms, this means a person only needs one altered copy of the FBN1 gene (out of the two copies everyone carries) to have the condition. If one parent has Marfan syndrome, each of their children has a 50% (1 in 2) chance of inheriting it, regardless of the child’s sex. This is often explained to patients using a simple coin-toss analogy where every pregnancy is an independent “toss,” so having one unaffected child doesn’t change the odds for the next.

However, about 1 in 4 cases (25%) occur in people with no family history at all. These are called de novo mutations or in simple words new mutation, where the genetic change happens for the first time in that individual, often during the formation of the egg or sperm, and was not present in either parent. In such cases, the parents’ risk of having another affected child is very low, though genetic counseling can help clarify this further.