F10 and Chronic Eosinophilic Leukemia, Not Otherwise Specified: In contrast, ultra-rare diseases, such as Niemann-Pick disease type C, factor X deficiency, factor XIII deficiency, and chronic eosinophilic leukemia, demonstrated exceedingly low incidence rates (0.0022 per 100,000 adults-year) and prevalence rates (0.042 per 100,000 adults) in our Albanian cohort.