Question About Genetic Testing

[blmoreschi]

My 11 year old was diagnosed in April. The rest of us (my husband, 13 year old daughter and me) were immediately tested for tTG etc and all came back normal. My husband and daughter (who is definitely his mini me) had numbers in the 0 and 1 range. Mine were in the 6 to 13 range.

 

In an effort to avoid testing everyone every 3 years if they don't even have the gene, we have started genetic testing. We assumed that the gene came from my side of the family because I have a sister with Hashimoto's, a brother with Crohn's and a first cousin with Celiac.

 

Not surprisingly, I tested positive for DQ2 and DQ8. What did surprise me is that my Celiac daughter only has DQ2 (and just one copy). My results came back before hers, so I figured she would have both.

 

Am I right in thinking that she has just one copy of DQ2 that it must come from me, and therefore we don't need to test my husband any further?

 

And we've decided to genetic test my older daughter when she's due to be retested (2-1/2 years) rather than run a tTG on her. No sense testing her every 3 years for the rest of her life if she doesn't have the gene. Right?

 

Does all this make sense? The doctors certainly seem to know less about it than I do!

[frieze]

no.  you can have celiac without DQ8 or 2.  and no, you husband contributed one gene to your daughter, he has two, you don't know which the other is.

[kareng]

no.  you can have celiac without DQ8 or 2. 

 

 

This isn't true.  At least not with current knowledge.  If you do not have a DQ 8 or DQ2 gene, you cannot have Celiac.  The DQ8 is the least common.  Only around 5% of people have this gene.

 

Open Original Shared Link

 

Open Original Shared Link

[frieze]

This isn't true.  At least not with current knowledge.  If you do not have a DQ 8 or DQ2 gene, you cannot have Celiac.  The DQ8 is the least common.  Only around 5% of people have this gene.

 

Open Original Shared Link

 

Open Original Shared Link

Last time I read, those two account for 98+% of celiacs, that leaves a few "unaccounted for".  Raven is a biopsy dx celiac, I do believe, and she has neither.....other countries recognize other genes.

[kareng]

Last time I read, those two account for 98+% of celiacs, that leaves a few "unaccounted for".  Raven is a biopsy dx celiac, I do believe, and she has neither.....other countries recognize other genes.

 

 

More info:

 

"What is the meaning of HLA DQ2/DQ8?

As an autoimmune disease, celiac disease is the consequence of the interplay between genes and the environment (gluten). We don’t know all the necessary genes to develop celiac disease; however, HLA DQ2 and/or DQ8 are absolutely necessary to develop the disease. Since 1/3 of the general population also have these genes, the presence of DQ2 or DQ8 does not imply that the person will develop celiac disease, rather, that they have a genetic compatibility with celiac disease. Conversely, the absence of DQ2/DQ8 almost certainly rules out celiac disease."

 

Open Original Shared Link

 

"Three conditions are necessary for celiac disease to develop: The person must have the genes (HLA-DQ2, HLA-DQ8, or both). The person must have been exposed to gluten (such as when a baby is given wheat cereal as infant food). Environmental or physiological (having to do with the body) factors may also contribute to the onset of celiac disease. -"

Open Original Shared Link

[frieze]

More info:

 

"What is the meaning of HLA DQ2/DQ8?

As an autoimmune disease, celiac disease is the consequence of the interplay between genes and the environment (gluten). We don’t know all the necessary genes to develop celiac disease; however, HLA DQ2 and/or DQ8 are absolutely necessary to develop the disease. Since 1/3 of the general population also have these genes, the presence of DQ2 or DQ8 does not imply that the person will develop celiac disease, rather, that they have a genetic compatibility with celiac disease. Conversely, the absence of DQ2/DQ8 almost certainly rules out celiac disease."

 

Open Original Shared Link

 

"Three conditions are necessary for celiac disease to develop: The person must have the genes (HLA-DQ2, HLA-DQ8, or both). The person must have been exposed to gluten (such as when a baby is given wheat cereal as infant food). Environmental or physiologillcal (having to do with the body) factors may also contribute to the onset of celiac disease. -"

Open Original Shared Link

Open Original Shared Link  too tired right now to continue, I wonder what Raven's opinion will be....

https://www.celiac.com/forums/topic/60270-one-half-of-a-celiac-gene/

[kareng]

Open Original Shared Link  too tired right now to continue, I wonder what Raven's opinion will be....

https://www.celiac.com/forums/topic/60270-one-half-of-a-celiac-gene/

I'm not trying to argue. I'm just putting some links to reputable Celiac Research Centers. Blogs and forum posts of people's experiences are interesting but not necessarily the best place to get your scientific info.

[blmoreschi]

Not to be really dumb here, but I'm not sure all that dialogue above actually answered my question.

 

If I have DQ2 and DQ8 (and no celiac) and my celiac daughter has DQ2, do we still need to have my husband tested or would she have gotten the DQ2 (she only has one copy) from me? I'm just not sure how the genetics work.

[1desperateladysaved]

Not to be really dumb here, but I'm not sure all that dialogue above actually answered my question.

 

If I have DQ2 and DQ8 (and no celiac) and my celiac daughter has DQ2, do we still need to have my husband tested or would she have gotten the DQ2 (she only has one copy) from me? I'm just not sure how the genetics work.

Have you one or two copies of DQ2?  It is possible to have 2 copies.  If you only have one copy, I don't think one could be sure which the child received.  Will the company that did the test help you by answering this question?  My understanding of genetics (which is very little) leads me to believe they can tell which genes the child has come from mother and father.

[blmoreschi]

Have you one or two copies of DQ2?  It is possible to have 2 copies.  If you only have one copy, I don't think one could be sure which the child received.  Will the company that did the test help you by answering this question?  My understanding of genetics (which is very little) leads me to believe they can tell which genes the child has come from mother and father.

Thanks for that info. I'll check into it further!

[frieze]

 

I'm not trying to argue. I'm just putting some links to reputable Celiac Research Centers. Blogs and forum posts of people's experiences are interesting but not necessarily the best place to get your scientific info.

are you from the northeast? if not you wouldn't realize that MGH is about as hide bound a conservative institution you might find.  and it has been generally acknowledged here at celiac.com that non 8 or 2 celiacs do exist, just a very small number.  why are you trying to exclude rather than include?

[kareng]

are you from the northeast? if not you wouldn't realize that MGH is about as hide bound a conservative institution you might find.  and it has been generally acknowledged here at celiac.com that non 8 or 2 celiacs do exist, just a very small number.  why are you trying to exclude rather than include?

 

 

This thread isn't about your opinions about medical research institutions or trying to argue with me.  I am not "excluding" anyone.  I just wanted the OP to see info from reputable research facilities.  .

[kareng]

 

Have you one or two copies of DQ2?  It is possible to have 2 copies.  If you only have one copy, I don't think one could be sure which the child received.  Will the company that did the test help you by answering this question?  My understanding of genetics (which is very little) leads me to believe they can tell which genes the child has come from mother and father.

 

 

Thanks for that info. I'll check into it further!

 

 

This is correct.  It isn't quite as simple as Middle School genetics but the basic idea stands. Genes are "double".  When an egg is made, it splits.  Each egg/eventual child gets 1 split half from the mom and one from the dad.  If you have the "gene" on only 1 half, it is possible the child won't get that half.  Therefore, she might have gotten it from Dad.

 

If you have 2 copies of it - then the child would get one.  But...Celiac genes aren't as simple.  There are alpha and beta alleles.....it gets really technical.  I would just get dad tested and know where everyone stands.

[blmoreschi]

This is correct.  It isn't quite as simple as Middle School genetics but the basic idea stands. Genes are "double".  When an egg is made, it splits.  Each egg/eventual child gets 1 split half from the mom and one from the dad.  If you have the "gene" on only 1 half, it is possible the child won't get that half.  Therefore, she might have gotten it from Dad.

 

If you have 2 copies of it - then the child would get one.  But...Celiac genes aren't as simple.  There are alpha and beta alleles.....it gets really technical.  I would just get dad tested and know where everyone stands.

Thanks - that's the simplified answer I was looking for!

[frieze]

This thread isn't about your opinions about medical research institutions or trying to argue with me.  I am not "excluding" anyone.  I just wanted the OP to see info from reputable research facilities.  .

and I was trying to help you, by expanding your knowledge about what we call "the General", lol.  and yes, your are excluding those very few persons who are not DQ2 or 8, such as Ravenwood.

[ravenwoodglass]

We all need to keep in mind that genetic research is really in it's infancy. There is a lot we don't know. Until they start doing genetic testing on every celiac diagnosed there will remain much to learn. I am a double DQ9 firmly diagnosed celiac. I am not alone. I don't have much time so only can provide one link. Here it is.

 

Open Original Shared Link

 

Evidence that HLA-DQ9 confers risk to celiac disease by presence of DQ9-restricted gluten-specific T cells. 

There are more peer reviewed journal articles out there if one wants to research further.

[kareng]

Once again - Genetic research is not the OP's question.  If you want to discuss research into other genes that may be associated with Celiac, start your own thread and discuss.  If you want to slam Mass General and Dr. Fasano, I'm not sure that would be a good new topic without some real evidence of whatever you are accusing Dr. F of doing or not doing.

[ravenwoodglass]

.

 

In an effort to avoid testing everyone every 3 years if they don't even have the gene, we have started genetic testing. .

 

 

And we've decided to genetic test my older daughter when she's due to be retested (2-1/2 years) rather than run a tTG on her. No sense testing her every 3 years for the rest of her life if she doesn't have the gene. Right?

 

Does all this make sense? The doctors certainly seem to know less about it than I do!

The reason I gave a reply previously with info on another gene that is associated with celiac was because of this part of your post. While gene testing can be a part of the diagnosis process just because someone does or doesn't have one of the two most common genes does not mean someone will or will not develp celiac.

Even if you older daughter doesn't show positive for DQ2 or DQ8 doesn't mean she may not develp the disease at some point. Are her chances greater if she does have them, yes.  You could chose to test her periodically until adulthood or you could choose to test her only if she develops symptoms. Do be aware though that celiac has many presentations so it may first appear as skin or mood issues not GI related ones. Many doctors forget or are not aware that celiac impacts much more than just the gut.

[frieze]

We all need to keep in mind that genetic research is really in it's infancy. There is a lot we don't know. Until they start doing genetic testing on every celiac diagnosed there will remain much to learn. I am a double DQ9 firmly diagnosed celiac. I am not alone. I don't have much time so only can provide one link. Here it is.

 

Open Original Shared Link

 

Evidence that HLA-DQ9 confers risk to celiac disease by presence of DQ9-restricted gluten-specific T cells. 

There are more peer reviewed journal articles out there if one wants to research further.

thanks!

[frieze]

The reason I gave a reply previously with info on another gene that is associated with celiac was because of this part of your post. While gene testing can be a part of the diagnosis process just because someone does or doesn't have one of the two most common genes does not mean someone will or will not develp celiac.

Even if you older daughter doesn't show positive for DQ2 or DQ8 doesn't mean she may not develp the disease at some point. Are her chances greater if she does have them, yes.  You could chose to test her periodically until adulthood or you could choose to test her only if she develops symptoms. Do be aware though that celiac has many presentations so it may first appear as skin or mood issues not GI related ones. Many doctors forget or are not aware that celiac impacts much more than just the gut.

my point, as well!  do not exclude on present knowledge.