Fred Trump III’s new memoir, All in the Family: The Trumps and How We Got This Way, shares fresh insights into the Trump family and acts as a platform to advocate for individuals with developmental disabilities.

Fred Trump’s own son William has a rare genetic disorder that causes severe developmental and intellectual disabilities. He says Donald Trump once told him to abandon William, saying, “He doesn’t recognize you. Let him die, and move down to Florida.” After a meeting in the Oval Office about dedicating more resources to people with disabilities, Fred Trump says his uncle said, “Those people, the costs. They should just die.”

“How could one human being say that about any other human being, least of all your grandnephew?” says Fred Trump, who calls on the next president to support disabled Americans. “The Harris campaign and her positions are ones that I believe. Now, that being said, I have yet to hear anything regarding disability actions … and I will put their feet to the fire on this.”