Table 3

Types of variants in β-thalassemia.

Gene	Variant type	Effect
β-globin gene	Transcriptional variants	β⁺ or β⁺⁺
	Primary RNA transcript processing	β⁰, β⁺, or β⁺⁺
	3’ UTR or poly-A site	β⁺
	Translation
	Initiation codon	β⁰
	Premature termination codon	β⁰

Abbreviation: UTR, untranslated region.