What is a C blood cell (Hb CC)?
The C blood genotype evolved from the A blood cell. It is formed when Lysine replaces Glutamic acid at position six of the beta hemoglobin chain. The replacement results in crystal formation of blood cells which leads to increased blood viscosity, cellular rigidity, and shortened red cell survival.
What happens when someone has CC genotype?
Hb CC is formed when Hb AC and Hb AC meets, in rare cases Hb AC and Hb SC. There are very few people living with Hb CC, this may be associated with the fact that most of them are miscarried because the Hb CC trait is associated with mild- severe cases of hemolytic anemia -a condition in which red blood cells are destroyed before their normal lifespan is over.
The lucky ones who survive are usually strong and healthy except that they have mild anemia disorders. In vitro studies have shown that there are lower parasite multiplication rates in Hb CC which explains the protective effect of Hb CC against malaria.
Can Hb AC and Hb AC get married without worries?
Yes, they can. According to the diagram, the chances of having an Hb CC child are 1:4. The child will either be miscarried or live healthily. However, even people have miscarriages due to other factors so it's worth giving it a try. Better than with AS or SC.
UPDATES: I found this wonderful new insight on Genotype. Read more below:
Is it possible that a couple with AA and AS who married each other give birth to SS?
Yes, it is not impossible! Couples that are AA/AS can give birth to a child with SS. This is the reason below:
1. Let me differentiate between hemoglobin genotype and hemoglobin phenotype
To get a particular GENOTYPE, you have to do a genetic testing or use two or more of the screening test (the conventional electrophoresis that we do + HPLC or other similar test) to confirm the true genotype, while hb PHENOTYPE is the appearance or characteristics of an individual haemoglobin on conventional electrophoresis which we slackly refer to as GENOTYPE.
Most times, when we call ourselves AA, SS, and AS, we are actually referring to our Haemoglobin PHENOTYPE and NOT GENOTYPE, because most of us don’t do genetic tests, all we do is hemoglobin electrophoresis.
2. Let us get the explanation of the concept of a thalassemic trait. Thalassemias are a quantitative defect of hemoglobin which means someone can be AA but the one or both A in this person is absent, otherwise known as thalassemia minor and major respectively. If such person runs hemoglobin Electrophoresis (the test that we always loosely regard to as genotype) only A band will be seen and such a person will be regarded as AA. But they are also prone to anemias and some certain abnormal features in the blood depending on the degree of the reduction in the defective A. such individuals can be Aβ-Thalassaemia (otherwise known as a thalassaemic trait) if one of the ’A gene’ is normal, or β-Thalassaemia major if both are affected.
3. Let us merge the two concepts above and to SEE THE DIFFERENT PHENOTYPE THAT EXISTS AND THE POSSIBLE CORRESPONDING GENOTYPE
If PHENOTYPE is AA, the likely GENOTYPES will be AA, Aβ-Thalassaemia.
If PHENOTYPE is SS, the likely GENOTYPES will be SS, Sβ-Thalassaemia (MEANING THE OTHER ‘A’ THAT WOULD HAVE MADE THIS AN ‘AS’ IS TOTALLY ABSENT.) Others might include SD, SG etc. though these are very rare.
If PHENOTYPE is AS, the likely GENOTYPES will be SA (NOTE – ‘S’ COMES BEFORE ‘A’ BECAUSE THE A IS THALASSAEMIC, THOUGH NOT TOTALLY ABSENT AS THE ONE ABOVE, IT IS SUBSTANTIALLY REDUCE), or truly AS.
4. Let us assume this our hypothetical couple have Hb electrophoresis done and was told that the genotype of partner 1 is AA, and that of partner 2 is AS, but the one that is called AA is actually Aβ-Thalassaemia as earlier mentioned. Their possible offspring include
I. AA, if the child inherits the normal A from partner 1 and another normal A from partner 2.
II. Aβ-Thalassaemia, if the child inherits β-Thalassaemic A from the partner 1 and normal A from partner 2.
III. AS, if the child inherits normal A from partner 1 and S from partner 2.
IV. Sβ-Thalassaemia, if the child inherits β-Thalassaemic A from partner 1 and S from partner 2.
Note that scenario I above will show AA on Hb electrophoresis, scenario II will show AA on electrophoresis, scenario III will show AS on electrophoresis, and scenario IV will show SS on electrophoresis.
I have tried to simplify the medical terms, but if you still have a doubt or clarification ask and I will try to shed more light, as much as I can.
You can read more here: https://www.google.com.ng/amp/www.graphic.com.gh/news/health/aa-and-as-partners-produce-ss-baby-is-that-possible.amp.html
It is also important to note that although Sβ-Thalasaemia and Hb SS are both forms of Sickle cell disease, they are completely two different disease conditions with far-reaching impact on the person suffering from them.
While Hb SS is as a result of a defect in the quality of hemoglobin, Sβ-thalasaemia is as a result of a number of hemoglobins present and to diagnose this one needs quantitative analysis of the hemoglobin chains whereas qualitative analysis is enough to diagnose SS which electrophoresis does.
Credit: Nairaland.
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