I am surprised that not all the genealogy and DNA web sites and genealogy programs do this. It certainly should be a major concern for every family. The following is an excerpt from a new entry in the MyHeritage Blog:
We are happy to release a new layer to your family history experience on MyHeritage: the Health Family Tree. This is a free feature, currently in beta mode and initially available to all MyHeritage users who have taken a MyHeritage DNA test or uploaded DNA data to MyHeritage, and who manage a family tree with at least 7 people in it. It will be made available later to many more users.
The Health Family Tree is a private and secure area on your MyHeritage family site, intended to help you document the health conditions of your close family members, both living and deceased, in one convenient place. You can then share this information (if you wish) as a printout. The motivation is simple: you’ll be able to communicate to healthcare professionals more efficiently information about health conditions that run in your family.
The Health Family Tree is not intended to replace your genealogy family tree and it doesn’t include functions for adding, editing or removing people. Instead, it is automatically created as a subset of your genealogical tree, and you can use it to conveniently annotate health conditions of your family members. The Health Family Tree is available only to family site managers. If you use it, nobody but you can see it, not even your own family members on your family site. In the future, we may provide options for you to share and collaborate on the Health Family Tree with other close family members that you select. If we do so, it will be opt-in so you will always be in full control of who can see the information. For now, the information remains for your eyes only. All information is stored securely.
You can read a lot more about this new offering, including instructions on how to access your Health Family Tree, in the MyHeritage Blog at: https://blog.myheritage.com/2018/05/introducing-the-health-family-tree.