In the Dungeon Master's Guide, page 263, it says:
As the Dungeon Master, you aren't limited by the rules in the Player's Handbook, the guidelines in this book, or the selection of monsters in the Monster Manual. You can let your imagination run wild.
On the following pages, some examples of rule changes are given, including modifying classes.
This means that if your group decides that it would be cool if warlock pacts could be inherited, then, yes, they could be. Your DM, as the 'Master of Rules', has the final say on whether it is possible and under what conditions.
EDIT: If you just look at the rules as written, the answer would have to be NO. On page 107 of the Player's Handbook, it is clearly stated that "At 1st level, you have struck a bargain with an otherworldly being of your choice." Nothing is mentioned of others being able to strike such a bargain for you or passing it on to you. In any case, that would not be "of your choice". Hence, a house rule would be required to allow this.