Thal Minor Alpha + Thal Minor Beta plans to have another child

Hello,

We found out that my wife and I have thal minor, but different kind (one of us is alpha and the other one is beta).  My wife's obgyn in Singapore told us that this is a unique situation and he will do some research and get back to us with the results.  He came back with an OK answer that this will not cause thal major.  Recently, we moved to Houston, TX and found another obgyn.  This time, he could not find the answer easily so he asked us to consult with a Hematologist or Geneticists.  In addition, I tried to research this information on the internet, but could not find it.  Btw, my daughter just turned 3 recently and she is healthy with no medical issue. Since we plan to have another child and knowing the fact that both of us are thal Alpha & Beta carrier, we want to make sure everything is okay.

Thanks.

In most cases, the combination of a beta minor and alpha carrier will not result in anything beyond beta minor condition. The exception is usually when three gene alpha is involved. When three gene alpha is combined with one beta gene, it can lead to thal intermedia. I would assume that whichever of you is the alpha carrier would be aware of the three gene status if you had it, as it does produce noticeable symptoms and in more severe cases can even lead to intermedia on its own. Since you describe it as alpha minor, I don't think there is any danger of producing an intermedia child. Major is impossible with this combination of genes.

Thanks for the quick reply. We never heard about the three genes alpha before.  I attached the latest thal screening done last year for me and my wife.  Maybe you could easily tell if my wife has just alpha thal without the three genes or anything else.  FYI - She does not have any problem with her health condition.  When you said alpha carrier and beta minor, what is the difference between minor and carrier? 

A brief explanation of the thalassemias is in order.

There are two beta hemoglobin genes and four alpha hemoglobin genes. In thalassemia, one or more of these genes is mutated or deleted. In beta thal if one gene is mutated the condition is thal minor, also known as carrier or trait. When two genes are mutated, the result is thal major or sometimes intermedia, depending on the type and size of the mutation, along with some other genetic factors. In alpha thal, there are four possibilities. Usually with alpha thal, the genes are totally deleted but occasionally mutated. When one gene is deleted it is silent carrier state. When two genes are deleted it is alpha thalassemia trait. When three genes are deleted, it is called hemoglobin H disease. Symptoms can vary widely, and sometimes patients will require transfusions. Four gene alpha normally results in the death of the fetus during pregnancy or at birth, as no useful hemoglobin is produced.

Your wife has been diagnosed as having alpha thal trait. This means two alpha genes are deleted. her Hb is borderline normal, so it is assumed it is trait and not HbH disease. DNA testing might possibly give a more precise diagnosis. I would agree from the blood tests that she does have trait, but it does not appear that anything more serious is at work, as her Hb is 11, and as you said, she has no health issues.

Your readings are quite interesting for a beta minor. Your Hb and red cell count are both high, which is unusual in beta minor. However, your low mcv and high amount of HbA2 indicates beta minor status. I am a bit concerned as to the source of your high ferritin levels. Have you ever had iron supplements? If not, then you have excess iron absorption from your diet and some alterations to your diet may be in order, such as drinking tea with every meal, as it inhibits iron absorption. Your current ferritin level is not yet dangerous but if it is due to excess iron absorption, it could pose a long term problem. Whatever you do, do not take iron supplements. And the same advice applies to your wife.

The only way to completely understand your thal traits would be do undergo DNA testing. From the results of your blood tests it does seem that your children would not be more than minors, but a DNA test could offer further assurance.

Thank you Andy.