Hi Adina,

The exon 4 mutation is a SV one.  I have seen this in two different sources---one from NIH, and one from something my son’s endocrinologist gave me---so am confident that this is accurate.

The way that I understand it "usually" to work, is that the "better" gene wins out.  So, if someone has one SW and one NC mutation, they will typically present as NC, because that is the "better" gene.  I think that is supposed to be true, if you have three mutations, as well.  My son also carries 3 mutations---1 SW, 1SV, and 1 NC, and he generally presents as NC. So, the theory seems to hold up in his case, at least.

I guess what I’m saying is that this "better" gene theory seems to be true in your case, as well. You carry a SV mutation (exon 4) and a NC mutation (the exon 7), but present with the "better" gene---the NC one---so genotype DOES seem to match phenotype.

Your children are a slightly different case.  If they each do carry a SW, SV, and NC mutation, then they would be expected to present---in theory, at least---as NC.  If they don’t, then---you’re right----they would both be examples of genotype NOT matching phenotype.

But I’m wondering whether they actually carry a different exon 7 mutation than you do.  You mentioned that your husband also has an exon 7 mutation?  Could it be that he actually has the OTHER exon 7 mutation---the SW one---and they carry HIS mutation, not yours?  If that were the situation, they would each have 2 SW mutations (exon 7 and intron 2) and 1 SV one (exon 4).  Following the "better" gene theory, they would then both present as SV’s, which is what they seem to do, and genotype WOULD, again, match phenotype!

Anyway....one other possibility to muddy the waters, even more!!!