Two cases of compound heterozygosity for Hb Hekinan [α27(B8)Glu→ Asp (α1)] and α-thalassemia in Thailand

Abstract

Two unrelated cases of compound heterozygosity for Hb Hekinan [α27(B8)Glu→Asp (α1)] and α-thalassemia have been found in Thailand. Mutations were established at protein level by peptide mapping and at the DNA level by direct sequence analysis. Proband S.S. had genotypeSEA/α2Aα1Hekinan, βA/βE, while an unrelated proband, S.J., is the first case described with the genotypeSEA/α2Aα1Hekinan, βA/βA. Both α1Hekinanmutations were located in the α1 locus. Hb Hekinan could not be accurately estimated by HPLC, since it was poorly separated from Hb A. However IEF gave good separation of Hb Hekinan and Hb A, leading to estimates of Hb Hekinan (α2Hekinan/β2Aand α2Hekinan/β2E) level as 40-43% of total Hb.