For some time now, women have been encouraged to test for Down Syndrome during pregnancy and to abort the child if the test is positive. Abortion is not simply tolerated but pushed as the responsible course of action. Consequently, the number of people with Down Syndrome has been decreasing to a point that is approaching extinction. In some countries, like Iceland, they have almost completely disappeared.
When a species of animals is in danger of disappearing from the world, it is common to declare them an endangered species. Many governments have legislation to protect such species.
The Canadian Down Syndrome Society is calling their campaign "Endangered Syndrome" to make the point that Western culture cares more about animals than human beings. Our culture protects animals that are in danger of extinction, but there is no protection for people with Down Syndrome. Not only that, as their numbers decrease, fewer resources are available to help them.
The campaign is ironically requesting that people with Down Syndrome be put on the Endangered Species list. This makes the point that the situation is so bad that it would be an improvement for them to be treated like animals. Of course, they are human beings and should not really be treated like animals.