Genetic Test Results

[elle's mom]

OK, the genetic counselor called me last week about the results of our kids genetic tests. Basically, all she told me was that my celiac diagnosed dd and my youngest dd both are positive for DQ2 & DQ8. My other two kids were negative for both DQ2&8. I have not received the copy in the mail yet, but she said that all the info on what genes the other two have is on there also. Due to finances, at this point we only got the kids tested and dh and I want to get ours tested eventually too, so we can then move forward with alerting the appropriate side of the family (or both).

The question I asked her was does the fact that there is one copy of DQ2 and one of DQ8 in our children mean that it is most likely that one comes from one parent and one from the other (one from myself and one from my husband)? She said no, that the two are highly associated and that mostly likely they both came from one parent. But everything I've read seems to say that you get one from each parent.........so is she just an idiot or am I really confused? She went on to say that there are four DQ's on chromosome 6 and that we get two from each parent. What worries me is that she didn't know 2 & 8 were the most common celiac genes until I asked her, she had to call me back. Apparently they are called something else on the report???

I will post the actual results when I receive the copy myself, but I was just wondering if anyone could clear this up for me. Thanks.

[Jestgar]

I'm going with idiot....

You get one copy of each gene from each parent. Both you and you husband carry either DQ2, or DQ8. You each have only one copy, or one of your other children would have at least one of them.

[nora-n]

yes, one from each parent.

She is wrong but was confused because she is on the right track but just read about it a little bit. She has not "got" it yet.

There are not four genes on gene 6, but two.

The number four is the alpha and beta chains together.

Those are linked.

Check the charts at wikipedia.

Like, for instance, allele one, DQ2 (HLADQ) had the alpha chain 0501 and beta chain 0201.

They often write it as DQA10501 DQB10201.

The other is allele two: anything, like for instance DQA10505 DQB10301 which is nicknamed DQ7. But note that it has the 05* alpha chain, and that is a celiac gene many labs forget to test for. Usual tests are just for the beta chains, like 0201 which they report as DQ2 and 0302 which they report as DQ8.....

You are right, she is wrongish.

She confused allele with alpha and beta chains.

So one child had DQ2 and one DQ8.

DQ2&8 are not linked at all.

Type in HLA DQ in Open Original Shared Link and read up on DQ there. It is the alpha and beta chains that are linked.

If one child had DQ2, one DQ8, the third none of them (but any of the other genes, like DQ4,5,6,7 and 9) nor the fourth, it MUST mean that mother and father have one of the celiac genes each. And the distribution is excactly like expected, with two having either gene, and the other two none.

Now DQ genes only account for 40% of the risk.

nora

[elle's mom]

yes, one from each parent.

She is wrong but was confused because she is on the right track but just read about it a little bit. She has not "got" it yet.

There are not four genes on gene 6, but two.

The number four is the alpha and beta chains together.

Those are linked.

Check the charts at wikipedia.

Like, for instance, allele one, DQ2 (HLADQ) had the alpha chain 0501 and beta chain 0201.

They often write it as DQA10501 DQB10201.

The other is allele two: anything, like for instance DQA10505 DQB10301 which is nicknamed DQ7. But note that it has the 05* alpha chain, and that is a celiac gene many labs forget to test for. Usual tests are just for the beta chains, like 0201 which they report as DQ2 and 0302 which they report as DQ8.....

You are right, she is wrongish.

She confused allele with alpha and beta chains.

So one child had DQ2 and one DQ8.

DQ2&8 are not linked at all.

Type in HLA DQ in Open Original Shared Link and read up on DQ there. It is the alpha and beta chains that are linked.

If one child had DQ2, one DQ8, the third none of them (but any of the other genes, like DQ4,5,6,7 and 9) nor the fourth, it MUST mean that mother and father have one of the celiac genes each. And the distribution is excactly like expected, with two having either gene, and the other two none.

Now DQ genes only account for 40% of the risk.

nora

Thank you so much!