Аннотация:This article proposes an approach to a comprehensive assessment of expert knowledge with using the model. Implemented the ability to account for a fuzzy and incomplete clinical picture of diseases. Based on the hypotheses, differential diagnostic series and comparison of reference models with personal models of new cases are formed, that allows to rate the degree of similarity and identify the disease. A comparative analysis of diagnostic hypotheses was carried out using special algorithms. The study was carried out on the mucopolysaccharidoses as an example, which belong to the class of orphan inherited lysosomal diseases.