When a story like this breaks, publications will often use it as a “news hook”. Many newspapers and magazines will try to find other people who also developed the disease at a relatively young age.
So it is a good time to pitch a story about it, especially if you can source a strong case study. In this instance, you would normally also need to speak to an expert who can talk about the causes of Alzheimer’s, symptoms and so on.
You can find case studies by contacting the press offices of relevant charities and doing a “shout out” on places like Twitter.
This is one reason why you should always keep an eye out for celebrity stories, even if you don’t want to write about celebrities.