Functional Implications of Rare Gene Mutations in aHUS Open the Door to Personalized Therapy

Hemolytic Uremic Syndrome (HUS) is a rare disease characterized by rupture of red blood cells (hemolytic anemia), low platelet count (thrombocytopenia), and thrombotic occlusion of small vessels (thrombotic microangiopathy), with prevalent involvement of the kidneys. SEU, in its typical form is caused by gastrointestinal infection with Escherichia coli. The atypical form of SEU (aSEU), which is not caused by an Escherichia coli infection, is a very rare disease that may have a genetic origin; it affects both children and adults and may occur in a sporadic or familial form. Many studies have shown that about 60% of cases of atypical HUS are associated with genetic abnormalities of the complement system (particularly the so-called "alternative pathway"), which is a key part of the immune system for responding to infection. Complement consists of a series of proteins that, when activated,