I wondered how often this happens. Turns out it has at least once.

Twins who were separated at birth got married without realizing they were brother and sister….

“Everyone has a right to knowledge about their lineage, genealogy andidentity. And if they don’t, then it will lead to cases of incest,”[Lord David] Alton.
Twins unwittingly got married in Britain

Technorati Tags: ineage, genealogy, identity