genotype and blood group compatibility

What you must know about Genotype and Blood Group compatibility

There has been a lot of focus on this topic in recent times, and it is only natural that we lend a voice to it in order to expand the horizon of the information about what you must know about Genotype and Blood Group compatibility. We did a little reading, surfing the internet, and asked questions to bring forth majority of the information you are about to get.

First things first, being assured of Genotype and Blood Group compatibility with your partner is one of the most important factors of long-term happiness in your marriage, it helps you raise healthy children, and saves you a lot of stress in the happy marriage you dream of with your partner.


Your genotype is your complete heritable genetic identity; it is your unique genome that would be revealed by personal genome sequencing. However, the word genotype can also refer just to a particular gene or set of genes carried by an individual. For example, if you carry a mutation that is linked to diabetes, you may refer to your genotype just with respect to this mutation without consideration of all the other gene variants that your may carry.

This is different from your phenotype which is a description of your actual physical characteristics. This includes straightforward visible characteristics like your height and eye color, but also your overall health, your disease history, and even your behavior and general disposition. Do you gain weight easily? Are you anxious or calm? Do you like cats? These are all ways in which you present yourself to the world, and as such are considered phenotypes. However, not all phenotypes are a direct result of your genotype; chances are that your personal disposition to cats is the result of your life’s experience with pets rather than a mutation in a hypothetical cat fancier gene. This article however focuses on the genotype and blood group compatibility, so we keep it that way.

The genotypes in humans are AA, AS, AC, SS, SC, CC.

Truth be told, I didn’t know there was any genotype like AC and SC until I was researching for this article and found it online.

Now let’s explain what all the AAs and ACs mean.

According to an online publication by Laumsites Ywc – What you have in your blood are cells, the most predominant of which are called RED BLOOD CELLS (RBCs).
These cells contain within them HEMOGLOBIN, a substance without which the RBCs are invariably useless.
This hemoglobin itself is composed of 2 parts: a heme (don’t bother yourself, this basically is a complex Iron-protein complex) and globin (2 pairs of protein chains, this is the important part).

There are 2 alpha and 2 beta globin chains – the pair, and there is a normal way the chains are supposed to be structured.
The error happens when a protein substitution occurs in any one of these chains – but particularly in the globin chains (First of all, you have to understand that amino acids are the building blocks of proteins – so if amino acid ‘x’ is the normal, an abnormality occurs when instead of ‘x’ at a particular location along the chain, you have ‘y’.)

There are different types of Hemoglobin; among them are Hemoglobin A, Hemoglobin S and Hemoglobin C.

Hemoglobin C is very rare.

Everyone must have a pair of these hemoglobin in their blood, each inherited from both parents. The pairing might be in any of the following formations: AA, AS, AC, SC, SS OR CC.

People with the genotype AA are prone to malaria sickness at their early ages. Sickle cell arises when there is any blockage in the blood vessels which inhibits the flow of oxygen. When the red blood cell do not have the required oxygen, there will be changes in its original shape (disc shape) to a “Sickle-like” or “crescent-like shape”, Thus, the name “sickle cell”. Sickle cell patients experience severe pains in body parts that lack oxygen flow. Their bone marrows will fail to produce red blood cells and this result to anemia. To save this crisis, blood is usually transfused to them.

SC, SS, or CC are Sickle cell diseases (a recessive disorder) –  a very serious medical condition with high prevalence rate in sub Saharan Africa. This is why intending couples must make sure to know their genotype and blood group compatibility before going ahead with marriage.

What is the Genotype and Blood Group compatibility that is good for marriage?

Study this table below carefully:

  • AA + AA = AA, AA, AA, AA
  • AA + AS = AA, AS, AA, AS, 
  • AA + SS = AS, AS, AS, AS,
  • AA + AC = AA, AA, AA, AC.
  • AS + AS = AA, AS, AS, SS,
  • AS + SS = AS, SS, SS, SS,
  • AS + AC = AA,  AC, AS,SS.
  • SS + SS = SS, SS, SS, SS,
  • AC + SS = AS, AS, SS, SS,
  • AC + AC = AA, AC, AC, SS.

Based on the table above, you can see that a person with the genotype AA can marry across. There’s no risk of having a sicklier for a child even when he or she marries an SS. An AA genotype person marrying an SS can only result in AS children. There’s no hope of having a child with the genotype AA. But there’s no danger either.

Someone with the genotype AS should only marry someone with the genotype AA because if AS marries another AS there’s one out of 4 chances (AS, AS, AA and SS) that they will have a child with the sickle-cell disease. Same applies when AC is combined. AC and AS combine will produce AA, AS, AC, SC, the sickle-cell disease will be SC.

Of course there are many cases where two abnormal was combined that is an AS and AS or AC and AC or AC and AS couples and had up to five or six children without a single sicklier among them. But there is no need to risk it? What if you’re not so lucky? Can you forgive yourself when you end up having a child with the sickle-cell disease and put the child through the agony the disease brings when you could have easily avoided it by doing a genotype and blood group compatibility test.

Compatible genotypes for marriage are:

AA marries an AA. That’s the best compatible. That way you save your future children from having to worry about genotype compatibility in future.

AA marries an AS. You’ll end up with kids with AA and AS which is good. But sometimes if you’re not lucky all the kids will be AS.

AS and AS should not marry, you already know what it can lead to.

READ THIS >  Lines you should not cross in a relationship

AS and SS shouldn’t think of marrying.

And definitely SS and SS must not marry since there’s absolutely no chance of escaping having a child with the sickle-cell disease.


The only thing that can change the genotype is an intentional act like Bone Marrow Transplant (BMT) Technology. It has been proven to be the only permanent cure to SS SC and CC; however, it is new, very expensive and cannot be done in any part of Africa. It also carries some risks.

Naturally, environment or time cannot change genotype.

Divine Miracles can change it as well – it has happened in so many part of the world. Again, some SS carriers may start experiencing crisis at late age (as late as 40s).  If these set of people go for test in a quack lab, definitely the lab technician will assume AA or AS since the person is not showing the symptoms. Later in life, it will become obvious when the symptoms starts appearing.



It is advisable that intending couples should know their blood groups before marriage.

The red blood cells that transport oxygen in the body carry two antigens, which are the A and B antigens. These antigens determine the blood group. The blood groups are designated by the letters O, A, B, AB. When the red blood cell carries only the A antigen, the blood group is ‘A’, it is ‘B’ when the blood cell has only the B antigen. When both A and B antigens are present, the blood group is ‘AB’. Finally, when there is neither A nor B antigen, the blood group is referred to as ’O’.

Here is the table that shows a cross breed of different blood groups and their products:

A + A = A or O
B + B = B or O
A + B = A, B, AB or O
A + O = A or O
B + O = B or O
A + AB = A, B or AB
O + O = O only


Blood groups have a hereditary basis and depend upon a series of alternative genes, a fact sometimes utilized in solving the problems of disputed parentage.

Equally important and linked to the blood group is the Rhesus antigen, also known as the Rh Factor, which is positive in 83% of the British population but about 95% among the black population.

You can be O Rhesus positive (O+ve) or O Rhesus negative (O-ve). When an Rh +ve blood is given to an Rh -ve person, then Rhesus antibodies are stimulated; for instance, immunization of a woman can result from blood transfusion or injection of Rh positive blood. In women also, immunization due to pregnancy can result from the passage of the Rh +ve antigen from a Rh positive fetus across the placenta into the circulation of a Rh negative woman.

It must be emphasized that when an Rh-ve woman is married to an Rh positive man, the chance for her becoming sensitized to the Rh antigen and thus having children affected with haemolytic (red cell breakdown) disease of the new-born is relatively small.

The risk of developing antibodies increases with succeeding pregnancies, thus if a Rh-ve woman marries a Rh +ve man, there is 1 in 143 chance of Rhesus iso-immunization during the first pregnancy, 1 in 14 during the 2nd and 3rd; 1 in 12 during the 4th, and 1 in 8 during the 5th pregnancy.

The overall incidence of haemolytic disease of the newborn due to this problem is about 1 in 200 of all pregnancies. Usually, sensitization due to pregnancy practically never results in haemolytic disease in the first child; on the other hand, sensitization due to previous blood transfusion may cause the first child to be affected. Thus the importance of avoiding the transfusion of Rh +ve blood to a Rh -ve person must be emphasized.

In conclusion, in view of the low risk of Rhesus iso-immunization, Rhesus factor does not constitute an absolute contradiction why a Rh -ve woman should not marry a Rh +ve man. Even in the few cases where sensitization occurs, the affected child can still be effectively treated. There is a drug that can be used to prevent sensitization if the Rhesus status of the couple is known initially. There is no risk of Rhesus iso-immunization if both couple are Rhesus +ve, or are Rhesus -ve, or if a Rh -ve man marries a Rh +ve woman.

Click here to read about how Rhesus Factor can cause miscarriages and affect pregnancy in your marriage.

A word is always enough for the wise, please be wise. Go for a Genotype and Blood Group Compatibility test before getting married.


If you are AS with another AS partner you are in love with, please read this experience as shared by my friend, Chiamaka:

“Some people have been reacting as if being AS is a form of disease or a disorder. This is wrong because as far as I’m concerned, it’s nothing to feel that way about. Nothing is wrong with someone who is AS.

The only concern is just about choosing who to make babies with. Every other thing is fine. I still believe it is that way because variety is the spice of life. Everyone should not be the same, therefore there shouldn’t just be one genotype available. As a matter of fact, there are some other genotype available but we will just concentrate on the three we all know which are AA, AS and SS to avoid complicated explanations.

The only genotype someone should not have is the SS genotype. This can only be avoided if people who are AS and SS marry ONLY AA genotype individuals.

May we all have the courage to do the right things at all times.”

It’s up to you now to decide. Do the safe thing and be happy in the future. Your genotype and blood group compatibility is very very important!!



About Admin

Olumide 'Glowville' Lawrence is a Digital & Social Media Strategist, Content/Concept Developer and Blogger with special interest in the fun side of relationships. His blog - - is his creative expression of how he views dating and relationships. Follow him on BBM: D610A114 | 08038273738 | | Twitter & Instagram: @oluglowville | Facebook: Olumide Glowville


  1. Pls I want to know the difference between AS and AC, SS and SC? Also, I want to know why it’s C.

  2. Two people that got married and they are always sick especially anytime they have sex it becomes it that their blood did not match or what?

  3. Wow… I enjoyed the reading and any couple should by all means do a check on genotype and blood group test before getting involved with each other….

  4. My fiance ando I are in love and about giving married when we discover we are both as. Can we marry and have only three kids?

    • Hi, everytime u give birth to a child, the probability of getting an SS is 25%. Some persons are unlucky and give birth to three children with the SS genetype, some are lucky and give birth to AA genotype. It’s not advisable for AS to marry AS. You might lucky, but then you might also get unlucky

    • Hi, thanks for this piece. I happened to find out I’m As,B+ while my Lady is also As. She has strong faith she wouldn’t give birth to As but I dont want to take a risk because its a very long relationship. Is there any help on possible outcome not having As if we have 3 children?

    • My reply is that there is a way out that is if you love her. There is a test you can carry out when a woman gets pregnant to know whether the foetus is SS or AA.If it is SS the foetus is flushed out.
      The good part is that the possiblity of having SS babies are nil

    • My partner and I are as and as will our first child be a stickler please help me do the math with x and y thing please

  5. Appreciate the article. Thanks.

  6. Thanks for the article article

  7. Nice article am exposed the more

  8. Two times i have broken relationship because of AS genotype. I just discovered the third one is AS too. What i need to do now? Can’t i marry her? if there is 1 chance out of 4?

    • It’s not a chance of 1 out of 4 children. It’s a chance of 1 out of 4 possibilities in every child. So you can get SS in your next 4 children if you are not careful. You may also be lucky and get AA or AS. But it’s better safe than sorry.

  9. Sir, is it possible for a doctor or reputable hospital to provide ones genotype without taking blood sample?

  10. Pls is it possible for ones genotype to be determine without blood sample taken

  11. wow, i was so scared anyways since am AS, but now am very much exposed, thanks very much 4 this article, it is really a lesson & i will make sure not 2 4get. Thanks a lot.

  12. Hi, I am As with Blood Group A+ and my husband is As with Blood Group O+. is there any other way to avoid having SS Child or not, since we have been married for almost 9yrs with out having children. any supplements to take before & After pregnancy.

  13. I am so grateful. I have never Ben tough understandably about genotype and blood group till I visited your website.thanks for this.may God reward you.

  14. Kubapire Richard

    Thanks for this piece I have learnt alot about this topic God blessed u

  15. this is very enlightening, thanks a bunch

  16. Stella please can i talk to you? It’s urgent.. I’d like to have your whatsapp contact.. Thanks

  17. thanks with these notification.

  18. Wow I am really blessed. God bless you real good for this article my 👍

  19. Can someone with A+ also possess AS genotype?

  20. Hi am aa and about to marry my man who s ss,I know at the end would have AS as children, my only concern is that I read in ur article that must ss don’t show crisses at early age , some come up later in their 40s. Rlly need to b enlightened. I rlly love my man regardless his geneotype.

  21. sir please if a man is AA and get married to AA as well maybe they gave birth to nine children what will be their genotype

  22. My girl friend is As group o+ and I am same As group o+ can we get married since group o+ is the best group, as you said o+o=o?

    • Please I need a rely to Zobs question because am in the same position
      Please because is so hard to end a relationship with some you love and loves you even yes the future has to be considered but if there is a way out
      Then chances can be taken
      Please rely Zobs question
      Thank you
      Before I forget Thank you so much for all the informations

    • Good evening
      Please rely me when he replies you
      Am having this same issue

  23. please i need clarity on this……
    my blood group is …………O
    my rhesus is ……………….. D+
    my genotype is ……………..AA

    but i don’t understand what they stand for at all and an i need to know if i safe.
    thank you in advance.

  24. Thanks for every bit of this info.

  25. does oyinbo faking us? how can a person having 0+ in blood group woul now exhibit AS as genotype when 0+ is the best blood group. pls can someone reason with me? thanks alot for your enlighting.

  26. Thank u guys for educating us we have learn a lot

  27. Am BG O+.What’s my possible genotype?Am a man.

  28. My son blood group is o positive, and genotyte of AC. IS THERE ANY RISK? THANKS SIR

  29. Hi, it has been a while that am into a relationship with my girl, later when test my genotype I discovered that my own is As ND her own too is As , can we marry ourselves, please I need advice and reply.thanks

  30. Hi IF ANYONE HAS AA AND SAME BLOOD GROUP. O. Is there any problem if your partner is in thesame

  31. please my question is that can someone with AS marry someone AC please house I really need a reply please house

  32. Hi,

    Thanks for this information, but please I would like to know if blood group A Rhed + and negative (-ve) for sickle cell marry; that’s being the in both? It would be much appreciated to advise me which blood group and sickle cell type I can marry.

  33. My girl friend is As group A+ and I am same As with blood group o+ can we get married ?

    • Your genotype is AS x AS, you may get married but not that for each pregnancy you have a 25% chances of having SS baby.

      You may want to think about it again before going ahead based on this.

      For the blood group, that is good to go but not for the genotype. Save your unborn kids the agony!

  34. am blood group B and genotype AA so can I marry any blood group and genotype can comes my way ?

  35. Wow!
    Nice piece of advice.
    I really appreciate ur effort…

    Pls,what are the full meaning of those genotypes AA, AS…………….. ?
    Thank in a million!!!

  36. Wow, that is great, keep the good works going. Pls I’m about to get married n this genotype this is really disturbing today. Pls enlighten me on this, can AB+ MARRY AN AS? Is there any possibilities of that happening thanks

  37. If I am AA can I get married to someone with SCD ? We will have any issues in the future with kids please reply

  38. Hi,

    Thank you for the article, so enlightening.

    My question is; a lady who is AA, A+ can she marry a man who is AS B-?

    Is their blood group compatible?

  39. my blood group is B positive how do i get to know my Genotype if it’s AA,AS and so on

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