Sitosterolemia: una causa poco conocida de hipercolesterolemia en la infancia

Sitosterolemia is a disorder of lipid metabolism characterized by an increase in plant sterols (phytosterols) in the blood. Its incidence is very low, with less than 100 cases published in the literature. It is due to mutations in the ABCG5 and ABCG8 genes that encode the sterolin 1 and sterolin 2 proteins, respectively, that form a heterodimer transporter (ATP binding cassette) that normally facilitates the elimination of sterols, producing an accumulation of phytosterols in blood and tissues. It can present with xanthomas, hemolytic anemia, macrothrombocytopenia and arthralgias. Cholesterol levels are usually normal although they may be significantly elevated. It is related to increased cardiovascular risk and premature death. Clinical presentation, management and evolution of two affected siblings, with no history of familial hypercholesterolemia or consanguinity, diagnosed in our center, is presented.