World Sickle Cell Day.

I was excited to wake up today and discover that today the 19th of June, is world sickle cell day. 

Sickle Cell Anaemia is often described as the 'silent disease', due to lack of knowledge about it. You may or may not know, I am a Scientist in training. Physiology modules which I have taken have given me the confidence to write this blog post.

Raising awareness about Sickle cell Anaemia is important in order to minimise it's impact on future generations. There is no cure for this disease, it is only Medically managed. Sickle cell is prominent amongst individuals of African/ Carribean descent. It is increasing in occurrence in the UK due to the diversity of ethnicities we have.

So what is Sickle Cell? 

Its is a disease of the blood, in particular the red blood cells; in which they 'sickle' or form a crescent shape. 

What does Haemoglobin have to do with it?

Red blood cells contain a quaternary (four subunit) protein called Haemoglobin. Haemoglobin is the substance oxygen binds to, then transports it to the respiring body cells and organs. Out of the four subunits there is a further division into Alpha-globin and Beta-globin. There are two A-globins and two B-globin assembled into the final haemoglobin structure. 

So what could possibly go wrong? 

A mutation occurs. Proteins are formed from amino acids. Amino acids must be in the correct order (Primary structure). This is because they have properties e.g. carrying a negative charge, allowing it to interact with other amino acids by form of for example attraction or repulsion; just like a magnet. So when everything is going smoothly, amino acids interact appropriately, correct folding occurs, Haemoglobin is assembled perfectly and can transport oxygen. 

An Amino acid substitution, can occur, for example a Valine to Glutamate on position/codon 7 in the chain. Valine has no charge, but glutamate carries a charge. CRISIS. Clumping or aggregates start to occur. 

Haemoglobin becomes inefficient in carrying oxygen. This leads to many physiological problems for an individual affected such as difficulty in breathing, quick tiredness and weak bones.

Whats the difference between an affected person and a carrier?

Okay ill try to explain this as simply as possible. 

Protein= Haemoglobin. Symbol=Hb/ H

Genotype 1 (gene inherited) = Normal. Symbol = A

Genotype 2 (gene inherited) = Sickle cell trait. Symbol = S

We always inherit two genes, one from our mother and one from our father. 

Sickle cell is a recessive gene, meaning for you to have sickle cell you have to inherit two sickle cell traits i.e. SS. 

Those who are carriers do NOT have the disease. They are AS, but have the risk of passing it on to their children.

Those with genotype AA are normal and unaffected.

Why should carriers be worried?

Let me place this chart for you. This is a cross between two carriers (AS) and the possible genotypes their children will inherit.

For more visual effect:

Ofcourse, there is a chance that sickle cell carriers don't have children with sickle cell. It is very possible, however the chances are on the low side. (One out of four)

Other possibilities:

Two sickle cell affected mating will unfortunately always give rise to sickle cell children. 

Those without sickle cell cannot have children with sickle cell. EXCEPT, if their partner is a carrier but even then they simply pass on the trait.

So it is now our responsibility, to make sure we know our blood types and that of our partner. In situations where both partners are carriers, or affected, genetic counselling can occur. Both parties can make informed decisions about reproducing.

I can't help but think about genetic engineering and the evolution of so called 'designer babies'. Scientists are proposing that soon, they may be able to genetically modify babies to become, smarter, more beautiful and in simple terms have more desirable traits. 

A lot of people are against it. But in my opinion, if these designer babies could be modified to be more healthy, then they should give it a go. Especially in life threatening diseases such as Sickle cell anaemia. Just my two pence piece.

Anyway, I hope you have learnt a thing or two from this blog post. Apologies if it was overly complex.

Thank you for reading! 

Peace & Chunks

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