The seventh son by Sebastian Faulks

When a young woman named Talissa answers an advert to carry a child, she cannot begin to imagine the consequences. Behind the doors of the Parn Institute, a billionaire entrepreneur plans to stretch the boundaries of ethics as never before. Through a series of IVF treatments, one they hope no one ever discovers, they set in motion an experiment that is set to upend the human race as we know it. Seth, a baby, is delivered to hopeful parents Mary and Alaric, but when his differences start to mark him out from his peers, he begins to attract unwanted attention.