So what is Sickle Cell Beta Thalassemia?

Its always interesting when the conversation of sickle cell starts because with me this is how it always goes…….

“I have Sickle Cell”

“Oh so you are SS?”

“Nope, I’m SBThal”

“Huh?”

And then I have to explain what it is and where it came from and how it is different from SS blah blah blah. 

I’ve been meaning to write this post for years but life……. and funnier stories kept on getting in the way.  So in my usual spirit of humour and profanity I will attempt to make this “biology” post as interesting and enlightening as possible.

So what is Sickle Beta Thalassemia and why is it different from SS?  To answer that question I need to start with the norm that most people are used to.

Sickle Cell is a genetic blood disorder cause by mutation which causes the body to generate red blood call that have abnormal Haemoglobin called Sickle Haemoglobin which causes the red blood cells to sickle…….. hence the Grinch.  Another side effect of this mutation is the life span of the red blood cells.  Yes your blood cells die – that is what your spleen is for!!!!  The spleen serves as ‘recycling plant’ for red blood cells.  It destroys the red blood cells and recycles the iron ready for your body’s bone marrow which creates new red blood cells.  Anyways the typical lifespan for a red blood cell is 90-120 days, but for someone with Sickle Cell the lifecycle is…… wait for it…. 10-20 days.  As you can imagine, the body can’t keep up with this accelerated rate of blood destruction which is why people with Sickle Cell are typically anaemic hence the term Sickle Cell Anaemia.

No two Sicklers are the same………. why?

The answer lies with foetal haemoglobin (HbF).  As the name implies, we are all born with it.  Foetal haemoglobin is contained within the blood cells we have at birth.  This form of haemoglobin is more resilient than even normal haemoglobin.  I’m not sure why there is a difference between foetal haemoglobin and normal haemoglobin but I’ll leave that to the experts to explain.  Remember I said the normal lifecycle of red blood cells is 90 -120 days well foetal haemoglobin has the same timeline.  So with most people, the body creates its own red blood cells  with normal haemoglobin and the blood cells with foetal haemoglobin die out……….. Not so with Sicklers, not sure why but don’t you you just love the human body?!  We still generate red blood cells with foetal haemoglobin…….. AWESOME!!!!!! 

So why am I going on about the wonders of foetal haemoglobin?  Because research has proven a positive correlation between high levels of foetal haemoglobin and reduced episodes of crisis.  So much so that one of the treatments for Sickle cell is Hydroxyurea – which promotes the generation of foetal haemoglobin, but we’ll get to that with another post.

Thalassemia, otherwise known as Mediterranean anaemia as you can guess is an inherited blood disorder that affects red blood haemoglobin.  it was first described in 1925, but wasn’t till 1946 its relationship to abnormal haemoglobin was identified.  Thalassemia has two types:

  • Alpha thalassemia occurs when a gene or genes related to the alpha globin protein are missing or changed (mutated). Common in persons from Southeast Asia, the Middle East, China, and in those of African descent.
  • Beta thalassemia occurs when similar gene defects affect production of the beta globin protein.  Common in persons of Mediterranean origin. To a lesser extent, Chinese, other Asians, and African Americans can be affected.

As mentioned before, Thalassemia is the production of abnormal haemoglobin which means that the again the life cycle of red blood cells are stunted which again means the patient will suffer from chronic anaemia.  So SBThal is the combination of both Sickle Cell genotype and Thalassemia.  Its inherited the same way Sickle cell is, view the image below.

SBthal

So what is the effect of the combination of Sickle cell and Beta Thalassemia?

I’m going to use my dad’s words – The half of your blood that is Thalassic is useless, doesn’t capture enough oxygen because of the mutation, the other half that is Sickle captures oxygen alright as normal but it prone to sickling.  This means people with SBThal have a high blood count but are anaemic because the haemoglobin is for all intents and purposes – low par.  There is an upside to this………… hee hee I know with every dark cloud there is a silver lining.  When my a crisis occurs i.e. my Sickle cells Sickle only half of my blood sickles, which means that I’m less prone to blockages i.e. strokes.  The textbooks state SBThal is considered a milder a ‘milder’ form of full blown SS.

In my case I would say that it has done NADA for my crisis episodes, apparently for SBThal I’m a bad case, but I appreciate that I could be worse off.

So I hope I have been able to educate you about my type of Sickle, I do intend to do some more research in to the other forms  and will write about them in due course 😀.

Any questions? Please do not hesitate to leave a comment and I will get back to you.

Toodles!!!!