Which disorder is known for affecting connective tissue and may lead to tall stature and heart issues?

Marfan syndrome is a genetic disorder that primarily affects the body's connective tissue, which provides structure and support to organs and other tissues. Individuals with Marfan syndrome often exhibit features such as tall stature, long limbs, and flexible joints. The disorder can also lead to significant cardiovascular problems, particularly involving the heart and blood vessels. For instance, it is associated with aortic dilation, which can increase the risk of aortic dissection or rupture, posing serious health risks.

The emphasis on connective tissue and the resulting characteristic physical features, along with the potential heart complications, makes Marfan syndrome the most fitting choice for this question. Other disorders listed, such as muscular dystrophy, neurofibromatosis, and phenylketonuria, affect different systems and do not share the same hallmark traits of tall stature or connective tissue involvement.