We describe a new δ/β fusion gene causing β-thalassemia (β-thal) trait and its formation mechanism. The proband was a 39-year-old woman who presented with persistent microcytic microcytosis without iron deficiency. Molecular diagnoses revealed a δβ configuration within a 54 bp region between the Cap site (+22) and codon 8, causing a deletion (NG_000007.3: g.63154_70565del). This results in a variant that has been named Hb Lepore-Hong Kong and shows a decreased β-globin mRNA in carriers compared to that of normal subjects. It is assumed that combination of this variant with β-thal may cause severe β-thal syndrome.
Keywords: Fusion gene; Hb Lepore-Hong Kong; β-thalassemia (β-thal); δβ configuration.