Perfect People - Peter James, Pan Books

Be careful what you wish for...John and Naomi Klaesson are grieving the death of their four- year- old son from a rare genetic disorder. They desperately want another child, but when they find out they are both carriers of a rogue gene, they realize the odds of their next child contracting the same disease are high. Then they hear about geneticist, Doctor Leo Dettore. He has methods that can spare them the heartache of ever losing another child to any disease - even if his methods are more than they can afford. At his clinic is where their nightmare begins. They should have realized something was wrong when they saw the list. Choices of eye colour, hair, sporting abilities. They can literally design their child. Now it's too late to turn back. Naomi is pregnant, and already something is badly wrong...