Hello and welcome to the zero definals podcast. My name is Tom and in this episode I'm going to be

talking to you about thalassemia. And if you want to follow along with written notes on this topic,

you can follow along at zero definals.com or in the hematology section of the zero to finals medicine

book.

Let's get straight into it.

Thalassemia is related to a genetic defect in the protein chains that make up hemoglobin.

So normal hemoglobin consists of 2 alpha and 2 beta globin chains.

And these 4 globin chains, 2 alpha and two beta, make up the hemoglobin molecule.

Defects in the alpha globin chains lead to alpha thalassemia and defects in the beta globin chains lead to beta thalassemia. Both alpha and beta thalassemia are both autosomal recessive conditions.

The overall effect of thalassemia is varying degrees of anemia and this depends on the type and

the mutation that's causing the condition. In thalassemia, the red blood cells are more fragile

and they break down more easily due to this defect in hemoglobin.

The spleen acts like a sieve to filter the blood and remove older blood cells.

And in thalassemia the spleen collects all the destroyed red blood cells and this results in spleenomegli as the spleen gets full of old

red blood cells. The bone marrow also expands to produce extra red blood cells to compensate

for this chronic anemia, and this causes a susceptibility to fractures and prominent features

such as a pronounced forehead and pronounce cheekbones

or malar eminences. So there's a few potential signs and symptoms to look out for in your exams.

The first is a microseiting anemia with a low mean corpuscular volume, which is why we call it

microcitic. They're small red blood cells.

Fatigue, palor, meaning pale skin, jaundice.

They can develop gallstones, spleen and megaly, as they get full of those old

...