I don't really know. It could be inspired by real-life incidents or completely made up. Maybe check the author's notes or reviews to get a better idea.
Yes, it is. There are real - life cases where certain behaviors or events related to abduction seem to be more prevalent within a family. This could be due to various factors like a family's history of criminal behavior being passed down through generations, or a dysfunctional family environment that leads to such extreme actions being more likely to occur within the family unit.
Perhaps it's a story of a family where abduction has become a sort of 'tradition' in a very dark sense. It might start with one family member committing an abduction and then others being influenced or having some sort of family - bound reason to follow suit. It could explore the psychological and social factors within the family that lead to such a disturbing pattern.