One of the downside of the embracing Chaos and its gifts are mutations, that would also affect the progenoid glands, necessary to create new Marines. In some cases (Rubric Marines), such organ completely ceases to exist.
So which of the Traitor Legions are still able to create new Marines "from scratch", not from converting loyalist or stealing geneseed from loyalist chapters?
I know that Iron Warriors definitely still do produce new Marines and the number of Thousand Sons is constant (they cannot be truly killed but also can't reproduce). Word Bearers are apparently surprisingly mutation-free, but what about such "gifted" legions like Death Guard, Emperor's Children or World Eaters?