Learning difficulties in Education are some of the most important causes of desertion. One solution has been to use learning and teaching tools in virtual learning environments. These tools facilitate the educational process and improve the cognitive processes in students. However, many tools do not consider the students' particular features, difficulties and levels of disability (all these features compose their profile) that may make it harder to learn. The adaptive virtual learning environments assists students to access course content, to interact with activities and to perform assessment processes, based in their characteristics, needs, difficulties and / or disabilities. This paper presents MDALS (acronym for Adaptive Learning Disability Model System) to characterize a disability and to identify potential difficulties that a student may have in their learning process. This system supports the development of virtual environments, providing personalized and / or adapted services, according to the students' context and profile, to assist their learning.