Did you know that love is not enough reason to marry someone? Your genotype and blood groups can be a major determinant on who you should get married to. If you and your partner have compatibility issues, it can result in giving birth to children with health complications like sickle cell anemia. This is because not every genotype and blood group is compatible. Types of genotype and blood group help determine the overall health of an individual including the kind of diseases they can pass on to their children. So it is crucial for couples to know each other’s genotype way before getting married so as to know whether or not they are compatible.
Did you know that there are advantages and disadvantages to having genotype aa? Here is everything you need to know about different types of genotypes, their characteristics and which genotypes are more vulnerable to diseases such as malaria.
But before diving in into which genotypes are compatible, it is crucial you understand genotype definition.
What is a genotype?
A genotype is the genetic composition of an individual. It also refers to the particular set of genes that an individual carry. A genotype tells you the full hereditary information, i.e., what you inherited from both your parents or what is passed on from parents to offspring.
On the other hand, phenotype are the physical characteristics in an individual, for example, eye colors, height. The kind of traits you possess is determined by your genotype and environment you live in.
Types of genotypes and their characteristics
Genotypes are divided into six groups and are distinguished based on the alleles that an individual has. AA, AS, AC, SS, SC, and CC.
The following are types of genotype in humans that an offspring is likely to have based on different genotype combinations of parents.
- 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.
Different types of blood genotype
Red blood cells transport oxygen in the body. It’s this same red blood cells that have antigens and Rhesus factor that determine a person’s blood group. The differences in blood groups are due to the presence or absence of antigens and antibodies. While antigens are located on the surface of the red blood cells, antibodies are in the blood plasma.
Did you know that there is more than 30 genetic blood group system?
And Out of these 20, only the Rh and the ABO system are considered during a blood transfusion. Furthermore, in the ABO blood system, not all blood groups are compatible. When incompatible blood groups are mixed during a blood transfusion, it results in agglutination. Therefore, before a blood transfusion is carried out, a medical practitioner has to do a cross-matching which is generally the process of determining whether the blood of a donor is compatible with the receiver.
When the RBC carry an antigen a, an individual is said to have blood type A. If the RBC carry antigen b, then the expected blood type is also B. However, when the blood cells have both a and b antigens, then the person has blood group AB. On the other hand, when your blood cells lack any antigen, then your blood type is O.
- People with blood group O are considered universal donors which means that they can donate blood to all blood groups.
- AB+ are universal blood recipients which means that they can receive blood from all blood groups.
- AB- people can receive blood from those with A-, B-, AB- and O-.
- A+ can receive blood from A+, O+, A- and O-.
- A- can receive blood from A- and O-.
- People with B+ blood types can receive blood donations from those with B+, O+, B- and O-.
- Individuals with blood group B- can receive blood from only two groups: B- and O-.
- If your blood type is O+, you can receive blood from those with O- and O+ blood groups.
- O- can only receive blood from O-.
Here is a summary of the types of genotype and blood group including the antigen and antibody that each blood group has.
Blood type B
Can either have genotype BB or BO, with an as the antibodies in the plasma and B as the antigens on red blood cells.
Blood type A
Has genotype AA or AO, antigens on the red blood cells are A and b antibodies in blood plasma.
Blood type AB
Blood group AB has genotype AB, antigens A, and B, no antibodies,
Blood type O
Has genotype OO, no antigens on red blood cells but has both antibodies a and b.
What exactly is a Rhesus factor?
Rhesus Rh factor is a protein found in red blood cells. This protein is inherited, and if you have it you are considered Rh positive, and if you lack the protein, then you are Rh negative. A child inherits the Rh factor from either parent. Therefore, it is crucial that pregnant women can get an Rh factor screening test during their first trimester.
Additionaly, if the mother is Rh- then an antibody blood test is done to ensure that there are no antibodies formed due to Rh + blood. If a mother has a different Rh factor from that of the baby, then she has to get Rh immune globulin injection in case the mother's blood ever comes in contact with that of her unborn baby.
Knowing the rhesus factor is crucial especially for pregnant women. This is because when a pregnant woman has a rhesus factor that contradicts with that of the unborn baby, it can cause Rh sensitization. For instance, when the blood of a pregnant woman who is rhesus- mixes with that of the fetus is rhesus + either during abnormal trauma or when you bleed it causes the production of Rh antibodies which can cause complications such as damaging the baby's red blood cells.
What's this means is that to avoid complications parents must have the same rhesus factor.
Types of sickling genotype
Sickle cell anemia also is known as sickle cell disease is caused by a gene mutation of the red blood cells whereby these blood cells are shaped like a crescent-shaped moon. The sickle cell gene is inherited so to have the disease you must inherit the genes from both parents. Children with only one copy of the gene are said to have sickle cell traits.
While symptoms vary from person to person the most common symptoms include anemia, severe pain, delayed growth, frequent infections and swelling of hands and feet.
Types of sickle cell disease
There are four common types of sickle cell disease
This is the most common type of sickle cell, and it occurs when a child inherits copies of the hemoglobin S gene from both parents.
Is another common type of sickle cell and occurs when a child inherits the hemoglobin C gene from one parent and hemoglobin S gene from the other parent.
This disease affects beta-globin gene production which results in the production of less beta protein which causes a reduction in the size of red blood cells.
It is the least common sickle cell, and it involves the beta-globin gene.
Other rare types of sickle cell anemia with less severe symptoms include hemoglobin SO, hemoglobin SE, and hemoglobin SD.
Types of genotype and their compatibility
How important is blood group compatibility for marriage?
Genotype AA can marry anybody of their choice even if it is SS; while AS should not marry AS or SS. the best match for SS is AA. AS are carriers of sickle cell anemia, SS are the individuals with recurrent anemia and SC are the ones with sickle cell disease.
In short SS and AC are considered the abnormal genotypes responsible for causing sickle cell. Therefore, when checking blood group compatibility for marriage couples have to be sure that both of them do not have abnormal genes which they can pass to their offspring.
On the other hand, someone with genotype SS should only go for partners with genotype AA because when two abnormal genotypes which are AS and AC combine they risk getting a child with sickle cell.
Couples that should not have an offspring together are those with genotype AS and AS, AS and SS as well as SS and SS. Furthermore, since blood groups have the hereditary information, they can be used in solving parental disputes.
What type of genotype is AA and what makes it more prone to malaria?
When it comes to marriage, a person with genotype aa can marry across many genotypes without risking getting a child with sickle cell except with AS genotype. When a person with genotype aa marries with genotype SS, it results in AS children. Therefore, genotype matchmaking for intending couples especially those with aa is to avoid any chance of getting an offspring with sickle cell disease.
So does that mean that people with genotype AA have more advantages?
According to research carried out by the University of Uyo in Nigeria, people with genotype AA are more prone to malaria with a percentage of 92.3 getting the parasite as compared to those with genotype AS and SS who had a lower infection percentage of 5.1 and 2.6 respectively.
The research also indicates that people with blood group O are more susceptible to malaria infection than any other blood types.
Another research carried out in Yemen supports the same finding in Nigeria whereby 44 out of 62 children with genotype AA were confirmed to have malaria. Out of the 62 children only 18 of those with genotype AS had the malaria parasite.
So does having sickle cell genotype AS protect you against malaria?
From the results of the two studies conducted in two different countries, it’s clear that those with genotype AA are more prone to malaria parasite while those with genotype AS sickle cell carrier are less susceptible.
This is because malaria parasites tend to thrive in bodies with perfectly formed RBC because they remodel this organelle. The survival of this parasite is also high where there are high amounts of hemoglobin. And since genotype AA are found in red blood cells with normal hemoglobin levels and a structure that can handle more oxygen binding capacity, it creates an environment where the malaria parasite can thrive and multiply.
On the other hand, people with genotype AS have some protection against malaria because the presence of the parasite in the body causes the red blood cells to rupture prematurely. The red blood cells in genotype AS also have abnormal hemoglobin structure and quantity meaning a lower oxygen binding capacity. These unfavorable conditions make it hard for the malaria parasites to survive.
One point to remember is that even though people with types of genotype SS sickle cell disease have a defective red blood cell and hemoglobin the protection against malaria doesn't apply to them. In fact, all types of genotypes are susceptible to malaria, and that’s why it is essential to take preventive treatments against malaria.
As a couple knowing each other’s types of genotype is very important as it tells both of you whether or not you are compatible. If you have compatibility issues and you let love cloud your judgment, modern medicine has proved biologically that you will give birth to a child or children with sickle cell anemia. Bear in mind that a child with this disease will not live long to fulfill their dreams, and during their short life, they will endure intense pain that can last between for a few hours to weeks, frequent infections and delayed growth.