In this report, we present the case of a patient diagnosed with Evans syndrome and primary biliary cholangitis, an unusual combination that to date has few cases reported in the literature. The patient presented complex clinical characteristics, which, based on epidemiological data, was first diagnosed as dengue with alarm signs due to positive IgG results for this infection; he presented with fever, jaundice with direct predominance of hyperbilirubinemia, anemia, alkaline phosphatase and persistent elevated gamma-glutamyl transpeptidase; for which additional laboratory and imaging tests were performed to consolidate the etiology of the symptoms presented, to finally be diagnosed with both conditions.

Down syndrome is a pathology that, according to WHO, has a high worlwide and national incidence, frequently associated with congenital heart defects. It affects the human genetic material and it is caused by the nondisjunction of chromosome 21 (XY, + 21 or XX, + 21) or other alterations associated with the same chromosome (mosaicism, translocation). It manifests itself with peculiar characteristics in various areas of the body, among which congenital heart disease stands out, mainly atrioventricular septal defects (AVSD), caused by mutations in the CRELD1 gene. This gene contains 9 exons, encodes cell adhesion molecules and at the same time acts as a regulator of the calcineurin / NFATc1 signaling pathway, thus allowing correct cardiac morphogenesis. On the other hand,  DS  brings  with  it  defects in  the  immune  and  respiratory system,&nb...