**1.4 Inheritance of genes for β-thalassemia and HbE**

Gene for β-thalassemia and HbE is transmitted within the family from parents to descendants in an autosomal recessive fashion. Thus, those who are heterozygous for abnormal β-gene are clinically asymptomatic and called β-thalassemia carrier or β-thalassemia trait. Those who are heterozygote for HbE gene (β<sup>E</sup> ) are also clinically asymptomatic and called HbE carrier or HbE trait. However, homozygote or compound heterozygote of the β-thalassemia gene and/or HbE gene are clinically affected and suffer from chronic anemia with some life-threatening complication. Therefore, accurate diagnosis of carriers of the β-thalassemia and HbE as well as the disease is important.
