title: Beta-thalassemia in the Korean population.
abstract: Beta-Thalassemia is uncommon in the Korean population, however, it must be considered in the differential diagnosis of hypochromic anemia. The molecular characterization of beta-thalassemia is absolutely necessary for molecular diagnosis as well as any genetic epidemiological study in this region. We analyzed the molecular basis of beta-thalassemia in 38 Korean families. Using direct sequencing of genomic DNA amplified through polymerase chain reaction and haplotype analysis, 35 beta-thalassemic genes were characterized, all of which were heterozygous. Twelve different mutations were identified. The most common mutations noted included the initiation codon ATG-->AGG (beta0) (28.9%), codon 17 (beta0) (A-->T) (18.4%), and IVS-II-1 (beta0) (G-->A) (10.5%). Interestingly, mutations causing dominantly inherited beta-thalassemia were also common (15.7%). All four cases with the IVS-II-1 (G-->A) mutation were linked to the silent mutation of codon 91 (C-->T) of the beta-globin gene. The initiation codon A7G-->AGG and IVS-II-1 (G-->A) with codon 91 (C-->T) mutations were found in the Far East only, and may be inherited from a common origin for each mutation, at least in Koreans. The codon 17 (A-->T) and codons 41/42 (beta0) (-TTCT) were suggested to be introduced by gene-flow from southern China. Otherwise, only Hb Korea [codons 33/34 (beta0) (-GTG)] and a novel beta-thalassemic mutation, codons 89/90 (beta0) (-GT), were identified in Koreans. This mutation spectrum is characteristic of the low prevalence area of beta-thalassemia in Korea, it is, however, quite different from the adjacent countries, Japan and China.
authors.affiliation: Department of Clinical Pathology, Seoul National University College of Medicine, Seoul National University Hospital Clinical Research Institute, Korea.
authors.forename: Sung Sup
authors.initials: SS
authors.lastname: Park
authors.forename: Young Joon
authors.initials: YJ
authors.lastname: Lee
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Kim
authors.forename: Sae Ick
authors.initials: SI
authors.lastname: Joo
authors.forename: Yukio
authors.initials: Y
authors.lastname: Hattori
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Ohba
authors.forename: Han-Ik
authors.initials: HI
authors.lastname: Cho
mesh_terms: D000328:Adult; D002675:Child, Preschool; D003062:Codon; D018387:Codon, Initiator; D005192:Family Health; D005260:Female; D006579:Heterozygote; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D009154:Mutation; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017086:beta-Thalassemia / Q000453:epidemiology / Q000235:genetics*
chemical_list: D003062:Codon; D018387:Codon, Initiator