In the first months of life, fetal hemoglobin disappears and the amount of hemoglobin E increases, so the subjects start to have a mild β-thalassemia. People who are heterozygote for hemoglobin E (one normal allele and one abnormal allele) do not show any symptoms (there is usually no anemia or hemolysis). There are cases associated with haemolysis.[4] Subjects homozygous for the hemoglobin E allele (two abnormal alleles) have a mild hemolytic anemia and mild enlargement of the spleen.