Thalassemia affects approximately 4.4 out of every 10,000 live births throughout the world. This condition causes both males and females to inherit the relevant gene mutations equally because it follows an autosomal pattern of inheritance with no preference for gender.
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Approximately 5% of the worldwide population has a variation in the alpha or beta part of the hemoglobin molecule, although not all of these are symptomatic and some are known as silent carriers. In fact, only 1.7% of the global population has signs as a result of the gene mutations, which is known as a thalassemia trait.
However, particular ethnic groups are more likely to be affected, with between 5% and 30% of these populations experiencing symptoms of thalassemia.
Alpha-thalassemia
Alpha-thalassemia is particularly common among certain populations of Southeast Asian descent. There is also a high number of carriers in Sub-Saharan Africa and Western Pacific regions. The prevalence of different population groups according to the geographical area of the world include:
- America: 0-5% of the population has a thalassemia trait, up to 40% of this population potentially being genetic carriers.
- Eastern Mediterranean: 0-2% of the population has a thalassemia trait, with up to 60% of this population potentially being genetic carriers.
- Europe: 1-2% of the population has a thalassemia trait, with up to 12% of this population being genetic carriers.
- Southeast Asia: 1-30% of the population has a thalassemia trait, with up to 40% of this population potentially being genetic carriers.
- Sub-Saharan Africa: 0% of the population has a thalassemia trait and up to 50% of this population potentially being genetic carriers.
- Western Pacific: 0% of the population has a thalassemia trait, with up to 60% of this population potentially being genetic carriers.
Beta-thalassemia
Beta-thalassemia is the most common form of thalassemia among populations of Mediterranean, African, and South Asian ancestry. The prevalence of different population groups according to the geographical area of the world includes:
- Americas: 0-3% of the population is affected by a gene mutation
- Eastern Mediterranean: 2-18% of the population is affected by a gene mutation
- Europe: 0-19% of the population is affected by a gene mutation
- Southeast Asia: 0-11% of the population is affected by a gene mutation
- Sub-Saharan Africa: 0-12% of the population is affected by a gene mutation
- Western Pacific: 0-13% of the population is affected by a gene mutation
What is Thalassemia?
Populations at risk
Both alpha- and beta-thalassemia are more prevalent in tropical and subtropical regions of the world, particularly where malaria is or has been endemic. Although the reason for this is not clearly established, this association is thought to be due to carriers of the genetic mutation having a higher degree of protection against malaria.
The southern regions of Italy and Greece are the most likely areas to be affected in Europe. The Maldives has a particularly high prevalence of thalassemia in Asia, with about 16% of the population reported having this condition. Other countries with tropical climates that also have higher rates of thalassemia include India and Thailand.
Related mortality
All types of thalassemia can be fatal in some cases, particularly when there are multiple gene mutations that affect the production of the globin chains. In 2013, 25,000 deaths were attributable to thalassemia, which was an improvement upon the 36,000 deaths recorded in 1990.
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