I applied to MSU, and you self report your grades to be admitted, I put in everything correctly but forgot to put a - on one of my 8 grades, and obviously they will see this when I have to mail in official transcripts, I put in everything else correctly, will that tiny mistake jeopardize admission?
I don’t think it will be an issue as the grade will be on your official transcript.
It said lying on your self reported grades can revoke admission though, all I did was forget a - on the end of one of the letter grades 
Rest easy. They will realize it was a typo.
You could just send an email about it.
Don’t send an email about it. As long as your grade wasn’t a D or F they won’t care.