Thalassemia, is a form of anemia quite common in the Mediterranian countries, is caused by errors in the gene splicing process.
Normal red blood cells contain correctly spliced beta-globin, an important component in hemoglobin that takes up oxygen in the lungs.

                                 scroll down

  Arrows mark 2 points of sites where point mutations causing thalassemia occur in the beta-globin gene.

The red blood cells in thalassemia patients are distorted and sometimes immature, containing a nucleus. This is due to a point mutation in the beta-globin gene, which causes an error in splice site selection. A faulty beta-globin protein is made, leading to severe anemia.
   back molecular genetics Back splicing