Alpha-Gene Triplication

Hi all,

I'm new to this board and try to find some information about Alpha Gene Triplication. I'm from Switzerland and happy that I have found this board with its great amount of information.

A few days ago I received the results of the blood testing of my daughter (15 months). The diagnosis is

Heterozygotic Alpha+ Thalassemia - Type Alpha-Gene Triplication Anti -3.7

No Beta-Thalassemia was found.

I do not have any detailed information about HB levels or anything like that as I have to wait until the doctor's consultation which is unfortuantely in a few weeks.

Now I tried to find some information about this specific Alpha Thalassemia (gene triplication) but its hard to find anything on the internet (except of hard to read scientifical studies). I also tried the search functionality of this board but could not find specific information about gene tripliciation (just that gene triplication could be a problem if there is also a Beta Thallassemia).

So my questions:
What is a gene tripliciation? Does that mean, that my daughter has three genes instead of two (like aa/aaa)?
Is it almost the same like the "normal" Alpha+ Thalassemia (like a-/aa)?
What is the impact to her life?
On the phone the doctor told as, that this is Alpha Thalassemia minor and my daughter will not have any problems with this disease but I read a lot of reports that Alpha+ Thalassemia does have impact on ones life.

Any information about the Alpha Gene Triplication is very much appeciated.

Thank you

Chris

Hi Chris,

There are normally 4 alpha genes, found in pairs on each of chromosome 16. When there is an alpha triplication, one of these pairs has one normal alpha gene and a triplicated (aaa) gene as its "partner" on that chromosome. You might see this written as alpha alpha/alpha alpha alpha 3.7. As you suggested, there is not a lot of difference between this and normal alpha genes. However, when combined with beta thalassemia, there are a wide range of possible outcomes depending on the specific beta mutation.

As long as this is your child's only thal mutation or deletion, the most you should see is a mild anemia, as is sometimes seen with alpha thal trait, where two genes are affected. However, the alpha triplication can vary in phenotype, so it can result in different outcomes. As long as no other thal gene is involved, it should never be a serious, transfusion requiring condition. Has the child shown any signs of anemia, lethargy, for example?

Hi Andy,

Thank you very much for your reply and your answers! Now it is clear for me what the Alpha Triplication is.

As far as I know, the alpha triplication is my daughter's only thal mutation. They tested her also to the Beta Thal bud did not find anything.

So far, I can not see any lethargy, she's even more energetic, but looks a bit "palish" (sorry do not know if these are the correct english words) sometimes.

Currently my and my wifes blood is tested to see who the carrier is and if there are also other Thals. We hope that just one of us is carrying the Alpha Thal and that there is no other Thal as we would like to have a second child.

Thank you again for all the information.

Chris

Chris,

It is likely that she will always have a mild anemia. Daily folic acid is the main recommendation. Hopefully, only one of you is a carrier. The triplicated gene is inherited from one parent only, so this may be all you have to deal with. If so, please do remember to educate your child about this once she is older, as this information is very important, so she knows that any partner should also be tested before deciding to have children of her own.

Hi Andy,

Ok, seeing that it could be much worse with all the different Thals, I think we can be "lucky" that it is the Alpha Thal minor only. The diagnosis of the Alpha Thal happend by chance. We donated the cord blood after birth in 2009 and a few weeks ago the hospital wrote us a letter that someone could use the cord blood but after they checked it, the have found the Gene Triplication. Until then we were not aware that one of us could be a carrier (and even did not know that this disease exist) as both do not have obvious signs of the amenia and also do not belong to one of the prevalent geographical clusters (like African, Asian or Mediterranean people).

Yes we will educate our child about this once she is older.

Thank you