Hb lulu island (α 2 β 2 107[G9]Gly→Asp)‐β°‐thalassemia (codon 15; TGG → TAG), a form of thalassemia intermedia

Hb Lulu Island [β107(G9)Gly → Asp] was discovered in an East Indian female who carried a common β°‐thalassemia allele, i.e., codon 15, TGG → TAG (is a stop codon) in trans . Both abnormalities were detected through sequencing of the amplified β‐globin genes and were confirmed by hybridization with 32 P‐labeled probes. Hb Lulu Island is mildly unstable with a borderline decrease in oxygen affinity; its instability is less severe than that of Hb Burke or β107(G9)Gly → Arg. The compound heterozygosity expresses as a thalassemia intermedia with moderate anemia, a variable need for blood transfusions, Heinz body formation, and a red cell morphology which is typical for such a condition. The level of HbA 2 was greatly increased (6.5–7.0%) as was the δ chain level (12% of total non‐α) probably because of the instability of Hb Lulu Island and the decreased ability of the β x chain to form dimers with the normal α chain.