Molecular characteristics of α+-thalassemia (3.7 kb deletion) in Southeast Asia: Molecular subtypes, haplotypic heterogeneity, multiple founder effects and laboratory diagnostics

Autor: Preawwalee Wintachai, Thanyaornwanya Charoenwijitkul, Phuthita Thepphitak, Kritsada Singha, Rossarin Karnpean, Goonnapa Fucharoen, Kanokwan Sanchaisuriya, Supan Fucharoen
Rok vydání: 2019
Předmět:
Zdroj: Clinical Biochemistry. 71:31-37
ISSN: 0009-9120
Popis: Objective The 3.7 kb deletion (-α 3.7 ) is the most common form of α + -thalassemia found in multiple populations which can be classified into three subtypes. In order not to mis-identify it, the molecular information within each population is required. We have addressed this in northeast Thai and Laos populations. Methods Screening for α + -thalassemia was initially done on 1192 adult Thai subjects. In addition, 77 chromosomes of Thai newborns and 26 chromosomes of Laos with -α 3.7 α + -thalassemia were also examined. All subjects were screened for -α 3.7 α + -thalassemia and subtyped by PCR-RFLP assay. Exact deletion breakpoint of each -α 3.7 subtype was determined by DNA sequencing. α-Globin gene haplotypes were determined. Results The proportions of -α 3.7 subtypes found in 216 Thai -α 3.7 chromosomes were 94.9% for -α 3.7I , 4.2% for α 3.7II and 0.9% for -α 3.7III . All 26 Laos -α 3.7 chromosomes were of -α 3.7I variety. At least six α-globin gene haplotypes were associated with the -α 3.7I α + -thalassemia. Conclusion All -α 3.7 subtypes were observed among Southeast Asian population. Haplotype analysis indicated a multiple origin of this common disorder in the region. A multiplex PCR assay has been developed for simultaneous detection of all subtypes of -α 3.7 α + -thalassemia as well as other α + -thalassemia found in the region including -α 4.2 α + -thalassemia, Hb Constant Spring and Hb Pakse.
Databáze: OpenAIRE
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