Genotype, actually known as haemoglobin genotype, is the state of the genes responsible for producing the protein segment of haemoglobin, the chemical substance that holds oxygen in every red blood cell from the lungs and releases it to every tissue in the body.
Normally, haemoglobin has 4 protein chains (known as 2 alpha chains and 2 beta chains) produced from specific genes; the normal haemoglobin gene is represented as HbA or A. However, when the gene that produces the beta chain undergoes an abnormal change (called a mutation) which is passed from parents to their child, the resulting haemoglobin (HbS or S) is inefficient in holding oxygen. In addition, the abnormal haemoglobin substances disfigure (sickling) the red blood cells housing them. As a result, oxygen will not be effectively supplied to the body tissues from the lungs and the red blood cells have a reduced lifespan from the normal 120 days to less than 30 days. This shortened lifespan means the sickle cells are destroyed quickly, putting the bone marrow under pressure to produce new red cells to replace them.
Everyone inherits one copy of every gene from their father and the other copy from the mother to have a pair. In this case, if a father is AS or SS, he will contribute either the A or S gene copy to any child he has; the same goes for the mother. So, the child ends up inheriting either AS (known as sickle cell trait) or SS (known as sickle cell disease) from the parents. But if one of the parents is AA (has two copies of normal haemoglobin gene) and the other has either AS or SS, the child will inherit either AA or AS. Children who are AS will live a normal life, but those who are SS (have sickle cell disease) have so many health challenges that will require constant medical attention. Many of them may likely end up dying before 30 years of age, especially if the parents are not financially capable of giving them the best medical care.
To avoid giving birth to children who are SS, every human being should know his or her genotype long before meeting the person with whom he or she will start a family. And how do you get to know your genotype? Must you go to a hospital to see a doctor first? The answer is no. In fact, when you have some health issues and visit a doctor, one of the important questions the doctor will ask you is whether you know your genotype.
Haemoglobin genotype is a test that doesn’t require a doctor’s recommendation before you do it. Simply walk into any medical lab that offers genotype test as one of their services and request to check your genotype. A sample of your blood will be taken with a needle and syringe, and you will be told to come back at a specific date to get the result which will clearly state whether you are AA, AS, SS, SC and so on. You may now need to visit a doctor in a hospital if you want a very detailed explanation and counselling on your genotype, especially if it is AS, SS or SC. Also, many hospitals have labs that offer haemoglobin genotype test as one of their services. So, you can get to do the test after a routine hospital visit for a checkup if you don’t know your genotype.
Couples who are both AS should ensure their babies are tested within the first one month so that those who are SS can be monitored and placed on early treatment. This also means the child stands a chance of being cured of sickle cell disease through what is known as bone marrow (stem cell) transplantation before the age of 16 if the parents have the financial capacity to fund it and the child meets the transplant criteria.
For more advice and help, consult a doctor online via The Reliance Care App.