If a father or mother of your proband is known to provide the pathogenic variant determined while in the proband, the chance for the sibs of inheriting the pathogenic variant is 50%. On account of lowered penetrance, sibs who inherit the pathogenic variant might or might not create aHUS (see https://industrialboilerrental75308.madmouseblog.com/12659362/air-handling-unit-ahu-hire-options