With those scores on the WISC, do not assume your DS is not gifted. As others have suggested, he may be twice exceptional.
While I know you're not trying to get your DS into a gifted program at this point, I suggest you keep in mind the position that the National Association of Gifted Children has taken regarding WISC use for selection into gifted programs, it takes the position that either the VCI or the PRI can be used in addition to the FSIQ or the GAI. Here is the paragraph:
The Verbal Comprehension Index (VCI) and the Perceptual
Reasoning Index (PRI) are also independently appropriate for selection to programs for the gifted, especially for culturally diverse, bilingual, twice exceptional students or visual-spatial learners. It is important that a good match be made between the strengths of the child and the attributes of the program. Students who have special learning needs should be admitted to gifted programs, provided that there are other indications of giftedness and instructional modifications are made to fit the needs of the students.This paper can be found here:
http://www.nagc.org/index.aspx?id=2455
