This is difficult to understand and hard to follow the statistics/DNA notation.
But look at Table 3 in the paper and look at columns 6, 7 & 8 and the combinations of As Gs Ts ( DNA notation) of affected and unaffected ,and of the unaffected carriers only ID 6:9 would look to be the one who is most likely to on set, the others most likely will not because they have at least one or both of the favourable modifiers AA , GG
I would wager that something like this will explain incomplete penetrance for the the past, and predict for the future, for other mutations/significant variants too in time.
My "avator" is one of Prof. Goodship's diagrams to illustrate it.
Cheryl my amended version did not save in time and the point I wanted to make about the 3 generation example mentioned earlier.Look at IDs 4.21 5.27 and 6.18 in Table 1- the Family Tree and then their AAs GGs combination in Table 3
Thank you, Len, for expounding the relevant points. Cheryl, it does boggle the mind a bit! I do think it is possible that family members carrying other aHUS mutations such as in MCP could have the protective CFH haplotype studied in this paper. And it is certainly possible that additional protective (and/or detrimental) genetic variants exist and will be found. At the Iowa meeting, Bu already mentioned mutated F10 (Factor X, a clotting factor) likely protecting some family members carrying a Factor H mutation from developing aHUS. He also just presented this at the American Society of Nephrology annual meeting; the abstract is available here.
Thanks Grace I was just about to post something on the aHUSUK website and so was able to update it with the ASN abstract http://ahusuk.org/why-do-some-at-risk-of-ahus-not-on-set-some-answe...