Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

[Q]: patau syndrome affects about one in 25,000 live births.
[A]: patau syndrome


[Q]: veronika marchenko is a russian activist.
[A]: veronika marchenko


[Q]: the river trent is one of the major rivers of england.
[A]:
river trent