Twenty years ago, Penn State professor Michael Bérubé wrote a book about raising his young son Jamie, who has Down syndrome. Jamie is now 26 years old. Michael has written a follow-up book, “Life as Jamie Knows It: An Exceptional Child Grows Up,” which explores Jamie’s growing independence, his difficulty finding a fulfilling job, and more. WPSU’s Adison Godfrey talked with Michael and Jamie about the book.