In most cases, aHUS is related to gene mutations, coupled with a triggering event.  Just having a gene mutation alone usually will not cause the disease. You need a gene mutation and a triggering event for a flare-up to start. Some examples of aHUS triggers are:

  • Pregnancy
  • Infections (from viruses and/or bacteria)
  • Cancers
  • Certain medicines

In other more rare cases, aHUS is related to the development of antibodies that attack your body’s own immune system. The reason some people develop these antibodies is unknown.

In aHUS cases where gene mutations and antibodies are not involved, the cause is not known.  Many researchers think that cases of aHUS where the cause is unknown are linked to mutations in genes that have not yet been discovered.