1 seedling of 4 looking deformed, light green patches and curling. Mosaic Virus?

First time grow but I've studied a LOT and sure everything is good as far as my controls. Using rockwool to grow, 600w MH lights, rooom temp constant 77F day 68F night. On day 13 from germination and three of the four look very healthy but what could be wrong with this forth one? Everything has been identical for each plant from same seedbank. Any advice would be greatly appreciated. Thank you all in advance.

I've attached photos of all four plants. The last two photos are of the one I'm having problems with.

Anyone? Please. Should I get rid of it? I've only germinated 4 with the intention of growing them in 20 gallon buckets. Do you think it will come around?