WASHINGTON — President Donald Trump on Sunday shared that he will have a "big" announcement related to autism on Monday afternoon at the White House.

The event, scheduled for 4 p.m. Eastern, will be closely watched by scientists and advocates.

Health and Human Services Secretary Robert F. Kennedy Jr. promised earlier this year to determine the cause of autism by September.

The announcement alarmed experts because Kennedy has promoted discredited theories that routine childhood shots cause the developmental disability. Kennedy has promised to execute a massive research effort to identify the disorder's causes, but has stayed mum on details regarding who is conducting that research and when it will be released.

Those who have spent decades researching autism have found no single cause

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