My Sister's Keeper by Jodi Picoult
This is a great read. How do parents face the horrible quandary of acting in the best interest of their children, when there is conflict of interest within the family? The parents want to save their child with cancer whose only hope of survival is the kidney donation from a perfectly matched donor. The other child, expressly conceived to become that sole organ (blood, or tissues, etc.) donor for her sister ... yet wants "medical emancipation" or the right to choose to donate if she so wishes.
The whole book is heavy reading and a tearjerker. The ending takes a surprising turn.