I'm sure programs are not legally able to discriminate against applicants with disabilities (i.e. learning/attention disorders), but would this make applicants much less desireable?
For example, if an applicant with a documented disability such as those mentioned above had a series of low board scores/shelf exam failures, followed by a series of very high ones due to remediation of the problem via new testing accomdations, etc., should this be mentioned in the dean's letter/personal statement as an explanation for the previous poor performance? Or will making mention of that hurt the applicant even more?
This is a very hard question to answer. Program directors are going to be wary of people whom have had poor performance on prior exams, for the obvious reason that it tends to predict future problems. However, if you have a track record of improvement, that will work in your favor. Thoughts to consider:
1. It depends on what you mean by "new testing accommodations". If you were given "official accommodations" (such as additional time, etc) by the USMLE, it will already be on your USLMLE transcript. Although it will not say what the accommodations were, it will mention "testing accommodations" on your transcript. So, in this case, the cat is out of the bag and it's probably worth talking about.
2. If the accommodations were all granted by your medical school, then you've got a bigger problem. Just because your medical school offered you accommodations, there is no guarantee (nor requirement) that others do so also. This has happened with MCAT/USMLE before -- the MCAT grants an applicant accommodations, but the USMLE does not. Each makes their own independent assessment as to whether you require the accommodation. So, whether you would be granted an accommodation for an ITE, Step 3, the ABIM boards, in house exams, etc, is all up for grabs. If you have been granted accommodations by the USMLE (who tends to be the most conservative of the group), then the rest will probably follow suit -- but there is no guarantee, especially concerning the ABIM.
3. Other than exams, does your disability have other far reaching effects? Would you need more time to write notes? Would you need a quiet place to do work on the wards? These can be problematic, and may not be covered by ADA. For example, let's say that because of dyslexia you write more slowly / need more proofreading. My residents usually admit 5-7 patients per night. If your disability prevents you from doing this full workload at an acceptable quality within duty hour limits, what happens? You can ask for an accomodation but I do not have to (am not legally required to) decrease your workload, so you can't ask to only have 3-5 admissions, nor can you have more time (as duty hour limits are absolute, and completing notes the next day would be unacceptable for patient care).
The bottom line is this: Most PD's would want to see that this is fixed, and that they would not need to do anything (perhaps short of giving you extra time on the ITE) to address it. The more unlike your situation is to this, the more it will hurt you.