Thalassemia Patients and Friends
Discussion Forums => Thalassemia Intermedia => Topic started by: alnarges on December 22, 2012, 06:40:53 AM
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dear freinds
recently I got my alpha thalassemia test and the result was :
alpha thalassemia 2 (3.7kb) positive.
my question is : I want to know if this result mean I have loss two genes or one gene ??? any one can help me because I can't understand this result because many Drs said many opinions.
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The 3.7kb deletion is the most common alpha deletion. It refers to one of the alpha genes in a cluster of two genes, being deleted. The other gene is normal. If this affects only one cluster, you are a single gene alpha carrier. If you have this deletion on both clusters, you would be a two gene carrier of alpha, but you would pass no more than one of these deletions onto your children, so if your partner was not a carrier, your children could have no more than one deletion. If your partner had a single deletion on both clusters, then your offspring could be two gene carriers. You could have a child with HbH disease only if your partner had two deletions on the same cluster.
Without the full report that references both gene clusters, I cannot tell you if you are a one or two gene carrier.
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thank you so much sir your answer help me 2 much and I will sent you my report if you can give me your email.
thanks a lot sir .
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andy@thalpal.com
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dear andy
I repeat the alpha thalassemia test and the result was :
Homozygous 3.7 kb deletion detected
not: this individual is likley to have the phenotype of alpha thalassemia trait.
now is this mean I lose two genes in same chromosome or in deferent chromosome???
my partner is alpha thalassemia silent carrier and sickle cell carrier only..
and what is the risk of this interaction ????
god bless you.
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The 3.7 kb deletion is a deletion of one of the two alpha genes in a cluster. Homozygous means that this same deletion occurs on both clusters. So each cluster has one alpha 3.7 gene and one normal gene. This means you can pass on only one of these pairs, so your child can receive only one alpha deletion from you. Since your partner has only one deleted gene, that is the most that can be passed onto a child, so the worst case is that the child would be similar to you, with one alpha deletion on each cluster.
There is one possible problem and that is that the 3.7 deletion can make it difficult to detect sequence variants that could also be there. So, tell me if your Hb level is fairly normal for a thal minor. If it is unusually low, it could be possible that you have HbH disease, but if your phenotype is thal minor, you can be confident that no other mutation is present.
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My HB is nromal 14.4
only RBC is smaller than normal.
ok .Now my partner also Sickle Cell Trait (Sickle Cell Carrier).
my question now : is there any interaction between alpha thalassemia and Sickle Cell Trait ??
best regards.
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Dear andy
god bless you
what we mean by alpha thalassemia 1 (20.5 kb) positive ???
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sorry dear andy
I forget this one also
alpha thalassemia 1 (--MED) POSITIVE
because I'm from arab gulf country
sorry again
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(--MED) is a common alpha deletion originating in the Mediterranean region. Both genes on that cluster are deleted. If combined with another two gene alpha deletion, the outcome could be alpha major or hydrops fetalis (fetus cannot live outside the womb).
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Dear Andy
Is there any intraction between alpha thalassemia carrier disease and Sickle cell anemia carrier if one parent is sickle cell enemia carrier and alpha cilent and the other parent is HOMOZYGOUS 3.7 KB deletion(phenotype) only???
best regards
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I don't understand what you mean by "alpha cilent."
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sorry I mean Missing one alpha thalassemia gene (silent carriers).
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The interaction to worry about here is not the sickle gene, but the alpha deletions carried by both parents. If I understand this correctly, one parent has a silent one gene alpha deletion while the other parent has homozygous 3.7 deletion, and that it a two gene deletion. There is the potential to have a child with HbH disease, which is typically a non-transfusing alpha syndrome, but it does include moderate anemia, so it is not desired even though it is not as severe as thal major. The sickle gene should not cause any issues when combined with alpha thal.
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Even the other one parent has homozygous(phenotype) 3.7 deletion in different clusters not in same cluster???
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If the alpha deletions are on separate clusters, then only one can be given to the child, so the result would be no more than thal minor.