Does anyone know if Abraham Lincoln had Marfan syndrome or not?

It is fairly certain that he did--by the looks of him at least--and that is some of the interested medical communities opinion. A good way to tell, without digging up and disturbing his humble remains, would be to check out his following relatives for Marfan Syndrome. I don't know if that has ever been researched yet.

i heard he did so do i ...but i've no symtoms that i know of email me if you want

I've heard that he might have. But I don't think they've actually proven it yet.

I don't think so... Would they even know how to diagnose it then?

He was likely manic depressive, however.

It's suggested that he did, but there's no way to know.

Some have suggested using DNA to test it (there's an extant shirt worn by one of the people who treated him after his assassination with his blood on it), but the technology is not yet advanced enough.

I have seen shows speculating that he did. He had the skeletal characteristics - tall, slender, and loose jointed. He also had the long, narrow face. I think they had done a few other tests to prove their theory that I don't recall, but they could be absolutely positive without a DNA sample.