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BTD Forums  /  Live Right 4 Your Type  /  Homozygous A and secretor status
Posted by: Vista, Tuesday, March 8, 2011, 4:45pm
I have recently been reading the thread "Alleles and MN subgroup" and after reading Dr. Tom Greenfield's blog, about this:  http://www.dadamo.com/B2blogs/blogs/index.php/2006/04/18/uk-ifhi-symposium-report-part-ii?blog=14, UK IfHI Symposium Report, Part II, about the different allele combinations, I also read about the different versions of allele combinations Ao, Oa, Ab, Ba and more in another interesting article:

http://www.dadamo.com/B2blogs/blogs/index.php/2006/04/10/uk-ifhi-symposium-report-part-i?blog=14

According to Dr. Tom Greenfield's blog about this, heterozygous secretors with one inherited Se gene may still have some of the characteristics of a non-secretor even though they secrete their ABH antigens.

I now know from 23andMe DNA testing, that I have two A alleles so I am homozygous for A and I also know from my parents bloodtypes that I have one A1 and one A2.

From this information I wonder if anyone knows if it is possible that I do not secrete the H antigen in gut mucosa and other secretions because I am homozygous for A and from blood testing I know that I am LDN, Le(a-b-).

I was thinking that individuals with the AO combination would probably secrete the H antigen because they have the O allele as well and therefore they would be secretors?

If so it would make sense to me because I can relate to a lot of stuff that I have read about non-secretors such as problems with caries and recurrant UTI's.

Posted by: Lola, Tuesday, March 8, 2011, 4:52pm; Reply: 1
instead of breaking your head over your secretor status, constantly
why not get a swami, if GTD is what you are currently following

you can input all your personal data
and also run it as a secretor
then again as a non secretor.....see if anything changes in your individualized plan

even input your haplogroup :)
Posted by: Captain_Janeway, Tuesday, March 8, 2011, 5:41pm; Reply: 2
You will still secrete H antigens if you are a secretor. Just not as much as someone who is a heterozygous A.
Posted by: Vista, Tuesday, March 8, 2011, 8:04pm; Reply: 3
Quoted from Lola
instead of breaking your head over your secretor status, constantly
why not get a swami, if GTD is what you are currently following

you can input all your personal data
and also run it as a secretor
then again as a non secretor.....see if anything changes in your individualized plan

even input your haplogroup :)



Thank you for your answer Captain_Janeway.

I already have SWAMIXpress and have already run SWAMI with all the info I have about Lewis, A subtype, haplogroups (both Y from my father, and mtDNA) and all the other data but I also find it interesting and want to understand things better. I am constantly learning from different sources. There's still a lot of things that I want to learn about, especially about genetics, blood and health issues.   :)
Posted by: C_Sharp, Wednesday, March 9, 2011, 1:35am; Reply: 4
If you have had genetic testing from 23 and Me their reports tell you what they think your secretor status is.

Why not use that determination, if you do not want to rely on your blood test results for Lewis status?

In 23 & Me just search for Secretor.

In the secretor search results, look at the reports for "Norovirus Resistance" and their explanation under the "How it works" tab.
Posted by: Kumar, Wednesday, March 9, 2011, 10:33am; Reply: 5
Thanks Vista for spotlighting the new developments. I have also come across some people who are apparently not "secretors" (we are very far away from the secretor status testing facilities of the worl!) but with some similar signs and heath issues. Not secreting glood group antigens into body fluids is an umportant health issue, but secreting very small amounts could mean "more or less" like a non-secretor in terms of health risks!
Posted by: Andrea AWsec, Wednesday, March 9, 2011, 2:44pm; Reply: 6
http://www.dadamo.com/science_abh-lewis.htm


Quoted Text
ABH secretors are almost always Lewis (a-b+) since they convert all their Lewis (a) antigen into Lewis (b). ABH non-secretors are always (Lewis a+b-) since they lack the FUT2 dependent glycosyltransferase to accomplish this. A small section (1-4%  of the population dependent on race) will be Lewis Double Negative (LDN; Lewis (a-b-))  and for which Lewis typing cannot be used to determine ABH secretor status. In these individuals determination via saliva is necessary. However, it may be helpful to think of LDN individuals as a special category of non-secretor, since they do lack the Lewis b antigen (like the traditional ABH non-secretors).  In  most instances LDNs share the same metabolic consequences as ABH non-secretors, and in a few, such as cardiovascular disease and insulin resistance, actually have the most severe variations.


Maybe I am not following you fully but.. Lewis (a- b-) are grouped with the non-secretors.. Lola is a- b-.
Posted by: Amazone I., Wednesday, March 9, 2011, 4:23pm; Reply: 7
but I found an  error here: A2 = AO isn't a real must but A2B can be the reply as well ;) ;D... even with a nonnie at my backside ;) (goofy)(whistle)
Posted by: Vista, Wednesday, March 9, 2011, 9:51pm; Reply: 8
I know about secretor status, 428G -> A in the FUT2 gene and according to 23andMe I am  Se/se, rs601338(A;G), but after reading  Dr. Tom Greenfield's blog about the different versions of allele combinations and that heterozygous secretors with one inherited Se gene may still have some of the characteristics of a non-secretor even though they secrete their ABH antigens, that made me think that maybe an A homozygous wouldn't secrete H since there is no O allele and that individuals with the AO combination would probably secrete the H antigen because they have the O allele and therefore they would be secretors.

I have also read that many individuals of blood group A phenotype may have the genotype AO, maybe as much as 90%:

http://www.dadamo.com/B2blogs/blogs/index.php/2006/04/18/uk-ifhi-symposium-report-part-ii?blog=14



If so it would make sense to me as I wrote earlier because I can relate to a lot of stuff that I have read about non-secretors such as problems with caries and recurrant UTI's.

Also another DNA testing sevice in Sweden are reporting that some of their customers tested as secretors seems to be resistant to infections with norovirus and they do not know what the reason for that is yet.

Also there are other FUT2 SNP's that are responsible for the non-secretor phenotype and some of them are rare. In Japanese people another mutation also causes the non-secretor phenotype, rs1047781(T;T).

http://www.snpedia.com/index.php/Rs1047781

http://www.wikigenes.org/e/gene/e/2524.html

http://blogs.discovermagazine.com/gnxp/2009/06/natural-selection-of-a-human-gene-fut2/



Since I have two A alleles and I know that my mother has A2/O blood and my father has A1/O I thought that I must have the A1/A2 combination.
Posted by: Lola, Thursday, March 10, 2011, 5:50am; Reply: 9
Did you ask your parents how they found out their A1 and A2 status?
you might be given the same test as well, no?
just to rest your mind
Posted by: Vista, Thursday, March 10, 2011, 10:39am; Reply: 10
Quoted from Lola
Did you ask your parents how they found out their A1 and A2 status?
you might be given the same test as well, no?
just to rest your mind


I do already know that I am A1 because I am a blood donor and my A1 father and A2 mother have also been blood donors. I also know what my grandparents bloodtypes were so therefore I know what my parents blood type combination of alleles are as I wrote earlier.

My wondering is not about if I am A1/A2, I wanted to ask if someone had the knowledge to tell if individuals who are homozygous A's therefore wouldn't secrete the H antigen in gut mucosa and other secretions.

My father who is an A1/O secretor Le(a-b+) (we know Lewis status because he donated blood) is also genetically tested as heterozygous secretor, Se/se.

I am also a heterozygous secretor but Le(a-b-) (blood testing) and when I was reading Dr. Tom Greenfields blog about this and the fact that heterozygous secretors with one inherited Se gene may still have some of the characteristics of a non-secretor even though they secrete their ABH antigens, I was thinking that maybe a person who lack an O allele wouldn't secrete the H antigen at all.


UK IfHI Symposium Report, Part I
http://www.dadamo.com/B2blogs/blogs/index.php/2006/04/10/uk-ifhi-symposium-report-part-i?blog=14

UK IfHI Symposium Report, Part II
http://www.dadamo.com/B2blogs/blogs/index.php/2006/04/18/uk-ifhi-symposium-report-part-ii?blog=14


Posted by: Vista, Thursday, March 10, 2011, 11:01am; Reply: 11
Quoted from Kumar
Thanks Vista for spotlighting the new developments. I have also come across some people who are apparently not "secretors" (we are very far away from the secretor status testing facilities of the worl!) but with some similar signs and heath issues. Not secreting glood group antigens into body fluids is an umportant health issue, but secreting very small amounts could mean "more or less" like a non-secretor in terms of health risks!


In Sweden it seems impossible as well to get tested for secretor status from saliva samples. The only way as far as I know to find out secretor status is to be tested genetically or if you are a blood donor there might be a chance that Lewis testing has been done when donating blood.

Is it possible to donate blood where you live?
Posted by: Vista, Thursday, March 31, 2011, 7:51pm; Reply: 12
It seems like some people of blood type A and B only secrete A or B substance and not H according to some articles I have found recently. From what I have understood, it seems like the amount of H that is secreted in individuals also is different and that the amount of H that is secreted is genetically determined.

That is why I am wondering if an homozygous A or B maybe would not secrete any H at all.


"Differences between families in the amount of salivary H substances"
http://deepblue.lib.umich.edu/bitstream/2027.42/66443/1/j.1469-1809.1962.tb01308.x.pdf

"ABH ANTIGENS IN NORTH INDIANS' Suraksha Agarwal ABSTRACT"
http://web2.sbg.org.br/gmb/edicoesanteriores/v11n1/pdf/a15v11n1.pdf

"Rev. Brasil. Genet. V, 4, 793-805 (1982) (Brazil. J. Genetics)"
http://web2.sbg.org.br/gmb/edicoesanteriores/v05n4/pdf/a12v05n4.pdf
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