If you are referring to your Sugar Black Rose seedling, there is nothing really to worry about, often the first few sets of leaves can be a bit "funny", but by the time the plant makes 4-5 sets of leaves, things are normally growing as they are supposed to do. At this stage just keep on caring for it and the plant will sort itself out soon enough and most probably grow into a completely normal plant. Sometimes though, plants like this will grow normally through veg and flowering, but once in a while will grow a funny leaf for absolutely no apparent reason. The quirk of growing the odd leaf once in a while will not affect flower quality, size or potency.
Hope this helps,..........
Organoman.