The final statistic quoted by Trump - that autism rates have risen to one in 31 - is correct. Trump also claimed on Sunday that California has a "more severe problem" with autism than other states surveyed by the CDC. Another claim made by Trump is around the effects of the mumps, measles and rubella (MMR) vaccine. Trump makes unproven link between autism and TylenolWhat is autism and what are Trump's unproven claims about a Tylenol link? Trust doctors over Trump on paracetamol, Streeting says In one 2010 study, a team of geneticists found autism occurred in approximately one in 271 Amish children.