Genetics and Consequences of Atypical Hemolytic-uremic Syndrome in Turkish Children

Atypical hemolytic uremic syndrome (aHUS) is associated with mutations or antibodies that affect the regulation of the alternative complement pathway. Several studies were published recently, describing these mutations. We present the initial clinical findings, treatments, and long-term follow-up results of 19 patients hospitalized with the diagnosis of aHUS. Methods. Nineteen patients who were diagnosed as aHUS were enrolled from January 2010 to March 2017. Initial clinical signs and clinical follow-up of patients with aHUS were evaluated. The reasons for complement factor H (CFH) mutations were investigated. Results. CFH mutations were detected in 5 of the 19 aHUS cases. Of these, one was novel, while four were previously reported. We reported here the clinical course of aHUS patients with CFH previously defined mutations (p.Glu936Asp, Val 1197Ala) and a novel mutation (Glu927Lys), which caused previously defined aHUS. Two of the CFH mutation cases developed end-stage kidney disease that required hemodialysis, and one patient developed chronic kidney disease. Two cases were in remission; one of them under supportive therapy and the other one in remission with eculizumab treatment. Conclusions. Morbidity rates are higher in children with aHUS. However, renal prognosis and morbidity rates are higher in children with CFH mutations than other children with aHUS. Poor prognosis in aHUS-children with CFH mutation depends on the genetic background.