Jeff Carter, youngest son of Jimmy and Rosalynn Carter, has lived with Parkinson’s for years

Jeff Carter, the youngest son of former President Jimmy Carter and First Lady Rosalynn, has been quietly living with Parkinson’s disease for the last several years, Jeff’s son revealed.

Josh Carter, 40, spoke about his father’s diagnosis on Monday at an event commemorating the 34th annual United Nations’ International Day of Older Persons.

While 72-year-old Jeff Carter has known about his condition for a while, he chose to keep it private until now, the younger Carter told People Editor-in-Chief Wendy Naugle during a panel discussion that focused on the “importance of strengthening care and support systems for older persons worldwide.”

“My dad is currently living by himself, he’s able to take care of himself, he’s independent, but he built his house knowing that one day he’s going to need more help,” he said, noting that his father moved into a wheelchair-accessible home about a decade ago so he could prepare for his future.

Today he “can literally control his brain with his iPhone, which is wild,” Josh Carter said. “He can stand up, he can walk around, he can hold a drink without spilling it, he can eat [and] he can communicate.”

After the panel discussion, held just days after Jimmy Carter’s 100th birthday, Josh Carter gave Naugle more insight into his father’s experience, saying he hasn’t been “very open about it because he doesn’t want to be the face of anything.”

“Parkinson’s sucks,” he said. “It’s a hard disease. It’s a hard diagnosis.”