An upcoming book by President Donald Trump s niece will detail his appalling treatment of his father, Fred Trump , during the years he battled Alzheimers disease .

Mary Trump, a clinical psychologist and the presidents only niece, has remained largely silent during her uncles rise to the presidency. But her book, Too Much and Never Enough: How My Family Created the Worlds Most Dangerous Man, is promising unsparing detail about the president and his relationship with his family when its released in this summer.

A description posted online by publisher Simon & Schuster noted:

She explains how specific events and general family patterns created the damaged man who currently occupies the Oval Office, including the strange and harmful relationship between Fred Trump and his two oldest sons, Fred Jr. and Donald.

Mary Trump will also detail the appalling way Donald, Fred Trumps favorite son, dismissed and derided him when he began to succumb to Alzheimers.

Mary Trump is the daughter of Fred Trump Jr., the presidents brother, who battled alcoholism and died in 1981 at the age of 42. Her grandfather, Fred Trump, is the presidents father, who died in 1999 at the age of 93 after suffering from Alzheimers disease. His death triggered a bitter family legal battle over the will.

Earlier this week, The Daily Beast reported that Mary Trump was the source of a New York Times report on the financial tricks the president used during the 1990s to help his parents duck millions in taxes, which also benefitted him financially.

Trump is considering a lawsuit in an attempt to block the publication of the book, The Times reported.

[Mary Trump] alone can recount this fascinating, unnerving saga, not just because of her insiders perspective but also because she is the only Trump willing to tell the truth about one of the worlds most powerful and dysfunctional families, the Simon & Schuster description stated.

Too Much and Never Enough: How My Family Created the Worlds Most Dangerous Man is set for release on July 28.