If a mum or dad of your proband is known to provide the pathogenic variant discovered within the proband, the danger into the sibs of inheriting the pathogenic variant is 50%. As a result of lessened penetrance, sibs who inherit the pathogenic variant may or may not build aHUS (see https://industrialchillerhire37148.blogsvila.com/32548873/the-air-handling-units-ahus-diaries