It’s more likely to be “just” appearance, but always be wary. The conditions are quite related in presentation, but “the fragile tissues and skin and unstable joints found in EDS are due to faulty collagen, while the features of Marfan syndrome are due to faulty fibrillin-1 and an over-expression of TGFβ.” I’m borderline with my clinical presentation. In the end, aortic and eye problems decide whether it’s Marfan or EDS.
“Many individuals have skeletal features that are similar to Marfan syndrome, but do they not have the aortic and eye problems that are characteristic of Marfan syndrome. This is called Marfan Habitus (or Marfanoid or Marfan-like Habitus). Often the skeletal features are inherited in families and can result from mutations in the same gene that causes Marfan syndrome.”
“It is recommended that individuals with major skeletal manifestations of Marfan syndrome have a thorough evaluation for the condition, including echocardiogram and ophthalmologic examination. Continued cardiac follow-up with echocardiograms every few years is recommended.”