The regulations for Public Law (P.L.) 101-476, the Individuals with Disabilities Education Act (IDEA), formerly P.L. 94-142, the Education of the Handicapped Act (EHA), define a learning disability as a "disorder in one or more of the basic psychological processes involved in understanding or in using spoken or written language, which may manifest itself in an imperfect ability to listen, think, speak, read, write, spell or to do mathematical calculations." (from Kidsource at NICHCY)
Since RTI has been evolving, one of my biggest concerns is that the areas of learning disabilities that are not reading based will not be serviced well. There are a plethora of research-based remediations and teaching methods now available for reading instruction, at least for the early years, and not much for the other areas of learning disabilities. I read some web entries today that has given me hope that math may be catching up, though I still question how soon solid interventions will be able to be put into place to assist our young ones with dyscalculia soon enough.
Dyscalculia Research Reveals Possible Cause by Amanda Windom
Down for the Count by Laura Blue, in Time Magazine