Is there a genetic factor to strokes?

Are strokes hereditary? It does seem that genetics can play a role in the risk for strokes .

Yes. There are genetic factors.
There are some people that are born with certain genes that predispose them to stroke. One such condition would be CADASIL (cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy). Some people are born with genetic conditions that predispose them to clotting. This in turn may increase their stroke risk. Finally, if you have a strong family history of high blood pressure, diabetes, high cholesterol or any of the major modifiable risk factors for stroke, you may also be at higher risk because of this. However, these particular conditions are very much treatable and you certainly can do something about them to lower your risk.

If you are interested, I am sure you can learn more about this condition from the below Web Family History and Other Characteristics That Increase Risk for Stroke