A rare disease is a chronic, debilitating, highly complex, potentially fatal pathology with a low prevalence, this being 1 per 2.000 people. People with a rare disease frequently go through different problems such as the lack of skills or knowledge of health personnel for the identification and timely management of these pathologies, with the consequence that the diagnosis is delayed or erroneous. For rare diseases, the use of genomic medicine allows, in many cases, to reach rapid and accurate diagnoses, as well as the complete identification and annotation of the causal variants. Once a pathogenic variant is identified, that is, a mutation, a diagnosis will be made and general or specific therapeutic measures can be implemented, as the case may be, together with prevention activities through genetic counselling. In this research work, three clinical cases of rare conditions are analyzed: an unusual odor disease with great affectation in the social relationship of the affected person, a family with neurodegeneration brain iron accumulation with hidden phenotype of mental illness was identified, and a person with Niemann-Pick disease being treated with a high-cost drug who was misdiagnosed.
