http://www.jehovahs-witness.com/topic/289385/thanks-mom-dad-oh-thanks-mother
In the link in the above thread, the Supreme Court of British Columbia upheld a couple's decision to give away (actually loan away) a large amount of assets to the Watchtower Society. It wasn't clear from that case if the children got anything at all, because that wasn't really the issue.
In almost every state of the U.S., parents can disinherit their children for any reason at all. A problem might come up if it is actually written in the will "and Susie gets nothing because of her [racial epithet] husband and child." Similarly, as the article says, it may not be enforced if it is tied to some contingency that's against public policy. For example "half of my estate to Susie, unless she is married to a Jew at the time of my death." But in the case the OP mentioned, there was nothing in the will that indicated the disinheritance had to do with racism. The racism came in through extrinsic evidence. So I don't think the same result would happen in the U.S. And honestly, I wouldn't be surprised if this decision gets overturned on appeal.
I assume that my own parents have disinherited me. Like Blondie, I would be rather surprised if they ended up leaving me anything.