Further identification of Hb G-Coushatta [beta22(B4)Glu-->Ala (GAA-->GCA)] in Thailand by the polymerase chain reaction-single-strand conformation polymorphism technique and by amplification refractory mutation system-polymerase chain reaction.

Thalassemias and hemoglobinopathies are very common among Southeast Asian populations, particularly in Thailand, where it is estimated that nearly 30% of the population carries at least one such disorder. Moreover, the heterogeneity of different mutant alpha- and beta-globin alleles contributes to the complexity in diagnosis and proper management, as more than 60 thalassemia syndromes and hemoglobinopathies have been described. Herein we report a further case of Hb G-Coushatta [beta22(B4)Glu-->Ala (GAA-->GCA)] (also known as G-Saskatoon, G-Hsin Chu and G-Taegu) in a Thai family in which the mother was found to have an unusual hemoglobin (Hb) anomaly in combination with Hb E [beta26(B8)Glu-->Lys, GAG-->AAG]. We applied our recently described polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique to scan the beta-globin genes and found an aberrant pattern in exon 1. The molecular analysis by direct genomic sequencing successfully identified the nucleotide mutation (codon 22, GAA-->GCA), and a novel amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) for this variant is described.