Many presidents lost family members before they moved into the White House. Theodore Roosevelt's mother and wife died on the same day. JFK's older brother, Joseph Kennedy Jr., died during WWII. Richard Nixon lost two brothers to tuberculosis. Donald Trump is no exception.
In the case of this president, Freddy Trump died relatively young. He was the namesake of Fred Trump (pictured below) and was quite different from his famous brother. To learn more about Fred Trump Jr., you can watch the video above.