Mary Trump will release "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man," on July 28, according to Simon & Schuster.

It marks the first time that a member of Trump's family will publish unflattering stories about the former real estate tycoon and reality TV star.

Mary Trump, 55, is the daughter of Fred Trump Jr, the president's older brother, who died in 1981 at age 42 due to complications from alcoholism.

The 240-page book will detail events she witnessed as a child while spending time at her grandparents' house in New York's Queens borough, where her uncle and his four siblings grew up.

"She describes a nightmare of traumas, destructive relationships, and a tragic combination of neglect and abuse," Simon & Schuster said in a blurb about the book.

Mary Trump, a clinical psychologist, will say that the president, despite being his father's favorite son, "dismissed and derided him" when he began to suffer from Alzheimer's.

In the book, she explains "how specific events and general family patterns created the damaged man who currently occupies the Oval Office," the publisher said.