SICKLE CELL DISEASE SUFFERERS; JUST BECAUSE SOMEONE MADE THE WRONG CALCULATION.

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I grew up in Nigeria hearing about sickle cell disease. A condition where children were always sick, having a crisis triggered by the smallest of events, and often missing school. We knew then that sicklers lived with this condition all their lives and it was often thought that they would usually die in their teens, and if they survived into their 20s then they may have escaped the most risky phase. I eventually got to know people who were sicklers as they are often called in Nigeria, mostly because they looked really thin and sickly, and were frequently absent from school. I did not know the underlying biology of it until I started studying genetics as a profession, and then I became astounded at the fact that the suffering of sickers is totally preventable. Let me explain.?

Sickle Cell Disease:

Every human has red blood cells. Those red blood cells are formed at the fetal stage by the information contained in our genes. In a healthy human, red blood cells are round in shape and help to transport oxygen to important organs like the heart and keep the body functioning on cue, pretty important stuff. But sometimes the red blood cells can be abnormal, with the curved shape of a sickle and reduced surface area for oxygen to bind, causing trouble for the organs that depend on it. Sickle cell disease is a genetic condition that happens when 2 parents carrying the gene for the formation of abnormal red blood cells have a child and that child gets one copy of each of these genes from both parents. Such a child has a lot of abnormal red blood cells that are unable to properly send oxygen around the body and the curved-shaped cells are not flexible enough to easily travel through blood vessels, resulting in pains and their bodies struggling to perform some relatively normal body functions.?

How Big Is The Problem:

Every year about 300,000 children are born with sickle cell disease. A large percentage of all individuals living with the disease identify as being from Africa, and in Nigeria alone 150,000 of these babies are born annually, meaning that half of the global sickle cell population live in Nigeria!

As soon as a child is born with this disease, it is irreversible, at least not yet by affordable technology available to the everyday African families, most of whom are currently living under the poverty line. The individual lives a life of pain and crises with the constant looming threat of early death. But unlike most medical conditions with similar levels of harm, sickle cell disease is totally preventable, and all it needs is a basic mathematical calculation that will make you holler in disbelief at the sheer simplicity of it.

Why Does This Problem Persist:

So two adults decide to get married and there is mathematics that must happen. Let us say that a normal red blood cell is formed by the gene denoted as A, and the genes for abnormal red blood cells are denoted as S. Now because genes occur in pairs, a potential mother who has one copy of the normal gene (A) and one copy of the defective gene (S) will be AS and a father who has the same will also be AS. At this stage they need to do some little mental genetic arithmetics; every time they get pregnant, the mum must give one set of these genes to the baby and the dad must do the same. In the unfortunate instance that they both give the S gene to the child, and for this couple there is actually a 25% chance that this will happen in every pregnancy, the child now has the SS genotype and is now consigned to a life of pain and agony. An innocent child grows to become an adult who must spend more time in the hospital than some nurses will do in their career, all because someone, actually 2 people, got the calculation wrong.?

Sickle Cell Maths:

Okay enough lamenting about the past, let’s get this calculation right and fix the future. For 2 potential parents, below are the calculations:

1. Both parents have normal genes AA x AA. All children will have the genotype AA and be born with normal red blood cells.
2. One parent has one of the sickle genes and the other does not; AS x AA. There will be a 50% chance of having children with one of the sickle cell genes (AS). These children are called carriers, they don't have the sickle cell disease, they are perfectly normal functioning people, but they can pass on the sickle cell genes to their children. There will also be another 50% chance that their children turn out to not carry sickle genes at all (AA).
3. Both parents have one copy of the sickle cell gene AS x AS. There is a 25% chance that every child that is born to them might inherit both copies of the sickle gene (SS) and these children will have sickle cell disease. There is also a 50% probability of having carriers (AS), and a 25% chance of having children with normal genotype AA. There is danger in this union!
4. If one parent has AS genotype and the other has SS, the chances of having a child with sickle cell disease increases to 50% and there is another 50% chance of having carriers. Double danger in this union!!
5. If both parents are sicklers SS x SS. Your guess is as good as mine, it is a disaster waiting to happen, one that should be avoided at all costs.

Conclusion:

So if you’ve stuck with me to this point you can see why I am surprised that Nigeria still has one of the highest cases of sickle cell disease in the world. We should be doing this calculation as often as we make the calculation of how many children we want to have. And before you say “I’ll take my chances”, think about the kids.?