Jan,
MDS is not described in terms of staging and level the way cancer is. (The debate about whether MDS is cancer or not is for another day--or at least for another thread!) There are two main classification systems used for defining the subtypes of MDS: the FAB (French-American-British) and WHO (World Health Organization) systems are well-described on
Wikipedia. The key criteria that separate the various subtypes are whether you have any chromosome abnormalities and, if so, which ones, and whether you have any blasts and, if so, as what percentage of the marrow. This is information that will come from your bone marrow biopsy and will help you understand where you fit into the family of syndromes that make up MDS.
Hope this helps.
Ruth Cuadra