Another QB

I know this thread is going to sound insensitive, but I don’t mean it to be. Today, Trent Dilfer’s five year old son died of heart disease. Doesn’t it seem that an abnormally large percent of NFL quarterback’s children suffer from birth defects/medical conditions? The ones I know off the top of my head are Jim Kelly, Boomer Esiason, Doug Flutie and now Trent Dilfer. Is there something here or am I just crazy?