Hb Koya Dora [α142, Term→Ser (TAA>TCA in α2)]: A Rare Mutation of the α2 Gene Stop Codon Associated with α-Thalassemia

Abstract

Hb Constant Spring [(Hb CS) α142, Term→Gln (TAA>CAA in α2)] and Hb Koya Dora [α142, Term→Ser (TAA>TCA in α2)] both involve mutations of the α2 gene stop codon and while Hb CS is the most frequent cause of nondeletional α-thalassemia (α-thal) in Southeast Asia, Hb Koya Dora is limited to a restricted population from Andhra Pradesh, India. Here we identify a homozygous case of Hb Koya Dora and confirm the structure of the 31 residue α chain extension.