In this post, we will be looking at the definition of the words genotype and blood group and why it is important to know your genotype and your blood group compatibility. We will also look at the tests used to determine genotype and blood types and which tests are offered by Bridge Clinic.
What is a Genotype?
A genotype is the entire genetic constitution of an individual, i.e. the genetic makeup of an organism or group of organisms with reference to a single trait, set of traits, or an entire complex of traits. In a nutshell: your genotype is your complete heritable genetic identity; the sum total of genes transmitted from parent to offspring.
There are four hemoglobin genotypes (hemoglobin pairs/formations) in humans: AA, AS, SS and AC (uncommon). SS and AC are the abnormal genotypes or the sickle cells. We all have a specific pair of these hemoglobin in our blood which we inherited from both parents.
Why it’s Important to Know Your Genotype
Knowing one’s hemoglobin genotype before choosing a life partner is important because there may be compatibility issues which could have devastating effects when it comes to conception.
Individuals with sickle cells experience severe pains in body parts where oxygen flow is compromised due to blockage in the blood vessels. Read about sickle cell disease here .
- AA can marry anybody
- AS is better off with AA
- AS and AS, AS and AC are too risky
- Two sickle cells = avoid conception
Types of Hemoglobin Genotype Tests
Newborn Screening | Diagnostic Testing | Carrier Testing | Prenatal Testing | Preimplantation Testing | Predictive and Presymptomatic Testing | Forensic testing
What is a Blood Group and Type?
To classify blood, antibodies and inherited antigenic substances on the surface are evaluated.
There are four blood GROUPS:
- Type A (marker A)
- Type B (marker B)
- Type AB (blood cells have both A and B markers)
- Type O (blood cells have neither A or B markers)
An Additional Marker in Blood: Rhesus factor
This is simply a protein that may be present on the surface of red blood cells. Some people have it and others don’t. If you have it, your blood type is further classified as positive; if you don’t, your blood type is further classified as negative. It is just a genetic difference (e.g. blue VS green eyes) and nothing to worry about. Therefore present Rhesus factor = Positive. No Rhesus factor = Negative.
- O- No A or B Marker
- O+ No A or B Marker + Rhesus factor (One of the Two Most Common Types)
- A- A Marker Only
- A+ A Marker but No B Marker + Rhesus factor (One of the Two Most Common Types)
- B- B Marker Only
- B+ B Marker but No A maker + Rhesus factor
- AB- A and B Markers Only
- AB+ All 3 Types of Markers: A, B and Rhesus factor
Why it’s Important to Know Your Blood Group Compatibility
It is important to know your blood type if you need a blood transfusion or if you want to donate blood. It also plays a role in determining paternity. Before a blood transfusion takes place it must be established that the donor’s blood type is compatible with the recipient’s blood type. The combination of certain antibodies (proteins protecting the body) can be harmful or even lead to fatal symptoms if antibodies perceive foreign cells as a threat. It is our immune systems’ way of protecting us.
Types of Blood Test
Complete Blood Count (CBC) | Blood Chemistry Tests | Blood Enzyme Tests | Blood Tests to Assess Heart Disease Risk.
Tests Offered by Bridge Clinic
1. HB ELECTROPHORESIS: Hemoglobin Electrophoresis Test (Code: HELEC P)
Hemoglobin is a protein that transports oxygen. Hemoglobin abnormalities, caused by genetic mutations, can result in certain diseases or disorders. This test is therefore used to detect abnormal forms and/or relative amounts of hemoglobin.
Why is this test done?
- Diagnose a blood disorder if symptoms suggest it
- Routine checkup as part of a blood test during a physical
- Screen for genetic conditions, e.g. sickle cell anemia, before conceiving.
- Monitor existing conditions
Bridge Clinic as also offers PGD and PGS . Preimplantation genetic diagnosis (PGD) can be performed during i n vitro fertilisation (IVF) to choose embryos without certain diseases/conditions. Additionally, some chromosomal abnormalities can be picked up during a preimplantation genetic screening (PGS).
2. Blood Type Test: ABO/RH (Code 1125 P)
During a blood type test, blood is tested for blood group antigens (ABO) and/or the Rh antigen. This test is done to:
- Ensure the right blood type is used for transfusions
- Check if two people could be blood relatives
- Check a pregnant woman’s blood type