I haven't seen it but have read of it, with some down time this evening I browsed a little for albinism in artichoke and it may not be all that uncommon in a given percentage from any lot of seed.

Several online mentions, and from Territorial Seed who I know to be reliable source of information- in their artichoke from seed description:
" Sow heavily and expect 70% germination. Of these seedlings, about 20% will not produce high quality plants. Cull out the small and albino plants."

Here is a link that might be useful: One mention at Territorial Seed