Hb lulu island (α2β2107[G9]Gly→Asp)-β°-thalassemia (codon 15; TGG → TAG), a form of thalassemia intermedia

Hb Lulu Island [beta 107(G9)Gly --> Asp] was discovered in an East Indian female who carried a common beta-thalassemia allele, i.e., codon 15, TGG --> TAG (is a stop codon) in trans. Both abnormalities were detected through sequencing of the amplified beta-globin genes and were confirmed by hybridization with P-32-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 beta 107(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 delta chain level (12% of total non-a) probably because of the instability of Hb Lulu Island and the decreased ability of the beta(X) chain to form dimers with the normal alpha chain. (C) 1995 Wiley-Liss, Inc.