Genotypes and blood groups

Knowing about genotypes and blood groups helps you make important health and life decisions. Genotypes and blood groups are passed on from parents to their children. There are four genotypes namely AA, AS, AC and SS, and four blood groups namely A, B, AB, and O. You can have only one genotype and one blood group.

When you are of African descent, making life-changing decisions like the choice of a partner means that it is important to know your genotype. Genotype is a trait that is passed from both partners to their offspring. There are four types AA, AS, AC and SS. The last two (AC and SS) are genotypes that cause sickle cell disease (SCD). Some combinations of genotypes increase the chances of having offspring with SCD. SCD can be avoided by matching with a a partner that has the right genotype:

• AA can partner with any other genotype. 
• AS can only partner with AA.
• AS partnering with AS or AC leads to a risk of having a child with SCD.
• SS and AC should only partner with AA.

Obviously, if you and your partner do not wish to have children or you would like to adopt a child,  then genotypes will not play a role in choosing your partner.

Knowing your blood group helps your healthcare provider with decisions about blood donation and blood transfusion. Your blood group determines whether you should receive blood from another person or not . The results of a mistake can be life-threatening. There are four blood groups A, B, AB, and O. In addition to a blood group, you also have a positive or negative rhesus factor. For example, your blood may be A+ or A-. These are examples show the effects of blood donations and transfusions:

• O+ can give blood to A+, B+, AB+ but can receive from O+ and O-.
• O- can give blood to everyone but can only receive from only O-.
• A+ can give blood to A+ and AB+ but can receive from A+, A-, O+, and O-.
• A- can give blood to A+, A-, AB+, and AB- but can receive from A- and O-.
• B+ can give blood to B+ and AB+ but can receive from B+, B-, O+, and O-.
• B- can give blood to B+, B-, AB+ and AB- but can receive blood from B- and O-.
• AB+ can give blood to AB+ but can receive blood from everyone.
• AB- can give blood to AB+ and AB- but can receive blood from AB-, A-, B- and O-.

Your blood group and genotype are determined through blood tests. Go to your nearest health facility or laboratory and request for these tests. The cost-free method of finding out your blood group is through voluntary blood donation. There are also home test kits for blood groups which are available at pharmacies or online.

About 3% of Africans is born with sickle cell disease (SCD), which may be prevented by knowing your and your partners genotype and making decisions about having children accordingly. Knowing your blood group can be key in situations where you or someone else requires a blood transfusion. Making sure that you know both your genotype and blood groups may prevent suffering and save lives.