Some of mine are doing that too. I have seen other posts from folks describing something similar.

This is my first time growing impatiens from seed so I don't know the answer, but I am not viewing it as a problem. The seedlings with some curled/drooping leaves are doing just as well as those without the trait. There is no sign of mites or anything else that looks like a concern and these seedlings are right next to some other flower and veggie seedlings and everything looks healthy.

I am going to chalk it up to impatiens looking odd from seed for awhile and see what happens.

What you are seeing is probably downwards cupped leaves. It is typically a response to too high levels of fertilizer, very saturated growing media, or root damage as result of transplanting. It does not have to be due to nerotic spot virus.

How much are you feeding them ?

I use a very (very) diluted fertilizer a week after germination and then start a regular (diluted) fertilizer program 2 weeks after germination.

Some starter mixes may contain a starter nutrient which is a bit high for the impatiens. Try to flush the root zone with plenty of clear water and occationally water 'from the top' but avoid washing away the young seedlings of course.

Other problems which could manifest themselves as downwards cupped leaves could be too low temperatures right after germination (try not to grow below 65 deg F at nights the first few weeks) or a cold draft.

Lastly, very saturated soil (excludes air) can also be the problem. Let the soil get moderately dry (do not draught stress them, though). Using a well aerated growing mixture is recommended.

If you are using Miracle Grow 15-30-15 then use 1/4 tsp fertilizer per gallon of water until the seedlings have 1 set of true leaves, and then follow up with 1/2 tsp per gallon of water every 2nd or 3rd watering after that.
If you use another type of fertilizer, prorate based on above. e.g. if you use 5-1-1 fish emulsion, then use 3/4 tsp initially and 1.5 tsp later.

I haven't fertilized them yet, and they're in a warm place, so I'm betting they're too wet. I just get so paranoid about seedlings drying out, I make sure I water daily. My other seedlings seem to be fine with it, but evidently impatiens don't like it.

Thank you!

Deanna