Missouri’s age limit for bone marrow donation is being challenged by a St. Louis teenager who says she wants to be a donor, but can’t because she’s a year too young. 17-year-old Elizabeth Dougherty says the age should be lowered to 16, allowing people her age to save lives. The bill lowering the age to 16 is sponsored by her father, Senator Patrick Dougherty. It’s under study by a Senate committee, and could be sent to the full Senate for debate next week.