You are right that there is some scatter, although it is not extreme. I have a 2e DS9, similar to yours, in that all of his scores pretty much come in above average, but there are some areas that his achievement is lagging behind his predicted ability.
In looking at your son's scores, you need to compare the look for a discrepancy of more than 15 points. This is the criteria that is used for defining a learning disability. Your son's FSIQ is 127, so when you look at the 4 subtests of the WISC, you should be concerned about anything that falls under 112. So for your DS, processing speed (which is commonly lowered by ADHD) is an issue for him even though it is above average. His VCI is borderline at 114, so he may have some issues going on there as well.
You get to the real meat of the matter when comparing the WISC scores to the WJ scores, again looking for that 15 point discrepancy. It looks like you are correct, that your son would be considered to have a disorder of written expression and a reading disorder. You can get even more detailed by comparing each of the 4 subtests on the WISC to their corresponding tests on the WJ, but that is beyond what I am familiar with. My DS used the WIAT and the neuropsych gave me a detailed report explaining his predicted scores on the WIAT based on his WISC scores. It was very insightful.
The frustrating part is what I am dealing with now. You know there is a "reading disorder" and a "disorder of written expression". But you these tests don't go any further in defining the disorders or telling you what has caused them and if they can be fixed. There are general accomodations that are suggested for children with a disorder of written expression....keyboarding, scribing, voice recognition software.
That's where my knowledge ends. HTH!
