“There were days I considered shutting the garage door and letting the car run until I was dead,” says Colorado mom Erin Griffin, of the time nine years ago when she learned that both her boys—not just her firstborn—suffered from autism. Brendan, her angular, dark-haired older child, was diagnosed in 1996 at age 4. Kyle, her round-faced, hazel-eyed younger son, was diagnosed in 1998 at age 2½.