Atypical Hemolytic Uremic Syndrome
Atypical hemolytic uremic syndrome (aHUS) is a disease that causes abnormal blood clots to form in small blood vessels in the kidneys. These clots can cause serious medical problems if they restrict or block blood flow, including hemolytic anemia, thrombocytopenia, and kidney failure. It can occur at any age and is often caused by a combination of environmental and genetic factors. Genetic factors involve genes that code for proteins that help control the complement system (part of your body’s immune system). Environmental factors include certain medications (such as anticancer drugs), chronic diseases (e.g., systemic sclerosis and malignant hypertension), viral or bacterial infections, cancers, organ transplantation, and pregnancy. In about 60% of aHUS, a gene mutation may be identified. The genes associated with genetic aHUS include C3,
CD46 (MCP), CFB, CFH, CFHR1, CFHR3, CFHR4, CFI, DGKE, and THBD. Mutations in these genes increase the likelihood (predisposition) to developing aHUS, rather than directly causing the disease. Most cases are sporadic. In familiar cases, predisposition to aHUS is inherited in an autosomal dominant or an autosomal recessive pattern of inheritance.
CD46 (MCP), CFB, CFH, CFHR1, CFHR3, CFHR4, CFI, DGKE, and THBD. Mutations in these genes increase the likelihood (predisposition) to developing aHUS, rather than directly causing the disease. Most cases are sporadic. In familiar cases, predisposition to aHUS is inherited in an autosomal dominant or an autosomal recessive pattern of inheritance.
Atypical hemolytic uremic syndrome differs from a more common condition called typical hemolytic uremic syndrome. The two disorders have different causes and different signs and symptoms.