What causes thalassemia?
You get thalassemia when you inherit gene mutations from one or both parents. These gene mutations cause you to lose red blood cells at a higher than normal rate and cause you to produce less hemoglobin.
The type of thalassemia you have depends on which mutated genes you inherit from your parents, and how many genes you inherit. There are 2 main types of thalassemia: alpha thalassemia and beta thalassemia. These are named after alpha-globin and beta-globin, the proteins that make up normal hemoglobin.
- Alpha thalassemia: This type of thalassemia involves 4 genes (you get 2 of these genes from your mother and 2 of these genes from your father). If you only get 1 mutated gene, you will have no signs or symptoms of thalassemia, but you can still pass on the gene mutation to your children (this is called being a “carrier”. If you get 2 mutated genes, you will have mild symptoms. If you get 3, you’ll have moderate to severe symptoms. A baby who inherits all 4 mutated genes will be very sick, and probably won’t live long after birth.
- Beta thalassemia: This type of thalassemia involves 2 genes (you get 1 gene from your mother and 1 gene from your father). If you get only 1 mutated gene, you’ll have mild signs or symptoms of thalassemia. If you get 2 mutated genes, you’ll have moderate to severe symptoms that usually develop in the first 2 years of life.
Who is at risk for thalassemia?
You are at risk for thalassemia if you have a family history of it. Thalassemia can affect both men and women. Certain ethnic groups are at greater risk:
- Alpha thalassemia most often affects people who are of Southeast Asian, Indian, Chinese, or Filipino descent.
- Beta thalassemia most often affects people who are of Mediterranean (Greek, Italian and Middle Eastern), Asian, or African descent.
Written by familydoctor.org editorial staff