谢谢帮顶医生说我是一种少有的亚裔ABO型血，有一种隐形的O An AB parent can indeed sometimes have an O child. But it is by no means common. In fact it would be fair to say that it is exceedingly rare. The one exception is in certain Asian groups. Some of these folks have a rare version of the ABO blood type gene called cis-AB. People with this gene version have an AB blood type but can easily have an O child. Don't jump to any conclusions! Sometimes an AB parent can have an O child.