The α0 -thalassemia 44.6 kb or Chiang Rai (–CR ) deletion has been reported in northern Thailand and is capable of causing hemoglobin (Hb) H disease and a lethal α-thalassemia genotype, Hb Bart’s hydrops fetalis, in this region. However, there are no current data regarding the frequency of –CR nationwide due to a lack of effective diagnostic assay. Therefore, this study aims to develop a reliable platform for simultaneous genotyping of –CR and two common α0 -thalassemias in Thailand (–SEA and –THAI) and investigate the frequency of –CR across Thailand. Multiplex gap-PCR assay and five renewable plasmid DNA controls for –CR, –SEA , –THAI , α2-globin (HBA2), and β-actin (ACTB) are newly developed and validated with reference methods. The developed assay shows 100% concordance with reference methods. The results were valid and reproducible throughout hundreds of reactions. This study successfully establishes a reliable molecular diagnostic platform for genotyping of –CR , –SEA , and –THAI in a single reaction. Additionally, it demonstrates the frequency of –CR in Thailand for the first time and provides knowledge basis for the planning of severe α-thalassemia prevention and control programs in Thailand, where thalassemia is endemic. Read the full article here.
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