Mistake in resume sent; what to do? I am asking this question on behalf of my brother, in the U.S.

Yesterday, my brother submitted his application to a Physicians Assistant program, which has a very rigorous application process (not very different from medical school in terms of rigor). However, today he noticed that when he uploaded his resume, the formatting was slightly changed; a few words went from being in all caps to all lower case. Also, he noticed that he had made one small typo.  

Would this look really bad and be percieved as carelesness? What should my brother do? As we see it, there are two options. Either do nothing, or send an email to the school explaining the situation (this seems like the best option to us). If the second is indeed best, how should he frame the email to minimize the damage?

Thanks.
You are risking drawing attention to a mistake that could otherwise go unnoticed. 

Is resume the main part of the application? Or are there other parts, like an essay, recommendation letter, some all-important exam (like GRE for graduate study)? 

Also, if there is time till deadline, consider waiting few days and then updating the resume with some new bit of information, like more detailed description of an experience that they might find relevant. An update to content is a lot more acceptable than fixing typos.