I believe that everything happens for a reason. And there could be a million different answers to that. One could be that it was caused by another human whom, within choice of his or her own freewill, decided to kill that child or baby. Or maybe the child or baby was ultimately born into a life that God couldn't stand watching the suffering that he or she would endure throughout their life and decides to end it prematurely while they are still young. God works in mysterious ways and I think that it is simply one of those things we can't understand until we can ask him ourselves.Or it could be the works of Satan and his demons. He could targeting a family and place the disease among the child and cause them suffering and death in order to dismantle and destroy the family all together.