How does a person inherit Marfan syndrome? Marfan syndrome is a genetic disorder that affects the body’s connective tissue, which provides support and structure to various parts of the body. Understanding how Marfan syndrome is inherited is crucial for individuals and families affected by this condition, as it can help them make informed decisions about their health and the potential for passing the disorder on to future generations.
Marfan syndrome is inherited in an autosomal dominant manner. This means that only one copy of the altered gene, which is located on one of the autosomal chromosomes (non-sex chromosomes), is sufficient to cause the disorder. If a person inherits the altered gene from either parent, they have a 50% chance of passing it on to each of their children.
The specific gene associated with Marfan syndrome is called FBN1, which codes for the protein fibrillin-1. Fibrillin-1 is an essential component of connective tissue, and mutations in the FBN1 gene can lead to the characteristic features of Marfan syndrome. These features may include long limbs, a long face, and heart problems, among others.
It’s important to note that not all individuals with a mutation in the FBN1 gene will exhibit symptoms of Marfan syndrome. This is due to the concept of penetrance, which refers to the likelihood that a gene mutation will lead to the disease. Additionally, expressivity refers to the variation in the severity of symptoms among individuals with the same mutation. This means that even if two people have the same mutation, they may experience different symptoms and severity of the disorder.
In some cases, Marfan syndrome can be inherited in an autosomal recessive manner, although this is less common. Autosomal recessive inheritance requires both parents to carry a mutation in the FBN1 gene and pass it on to their child for the child to have the disorder. The chance of having a child with Marfan syndrome in this scenario is 25%.
Genetic counseling is often recommended for individuals and families with a known or suspected Marfan syndrome mutation. A genetic counselor can provide information about the inheritance pattern, the risk of passing on the mutation, and the potential for recurrence in the family. Additionally, genetic testing can confirm the presence of the FBN1 mutation and help with diagnosis.
Understanding how a person inherits Marfan syndrome is vital for those affected by the condition. By knowing the inheritance pattern, individuals and families can make informed decisions about their health, seek appropriate medical care, and support each other in managing the challenges associated with Marfan syndrome.
