title: Beta-thalassemia mutations in the Portuguese; high frequencies of two alleles in restricted populations.
abstract: We report the characterization of seven different beta-thalassemia mutations in 131 newly diagnosed Portuguese beta-thalassemia heterozygotes. Methodology included the detection of abnormal fragments by agar gel electrophoresis of PCR-amplified DNA fragments after digestion with specific restriction endonucleases, as well as hybridization with synthetic nucleotide probes and sequencing of amplified DNA. Four mutations, including the newly discovered TGG-->TGA change at codon 15, occurred in excess of 10% and accounted for some 90% of the beta-thalassemia alleles in this population. The geographical distribution is uneven; the TGG-->TGA mutation at codon 15 was primarily observed in the coastal region north of Lisbon, while the IVS-I-6 (T-->C) mutation was confined to the central part of the country.
authors.affiliation: Department of Hematology, Centro Hospitala de Coimbra, Portugal.
authors.forename: G P
authors.initials: GP
authors.lastname: Tamagnini
authors.forename: P
authors.initials: P
authors.lastname: Gonçalves
authors.forename: M L
authors.initials: ML
authors.lastname: Ribeiro
authors.forename: J
authors.initials: J
authors.lastname: Kaeda
authors.forename: F
authors.initials: F
authors.lastname: Kutlar
authors.forename: E
authors.initials: E
authors.lastname: Baysal
authors.forename: T H
authors.initials: TH
authors.lastname: Huisman
mesh_terms: D000483:Alleles; D001483:Base Sequence; D003062:Codon; D004252:DNA Mutational Analysis; D005260:Female; D005914:Globins / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D011174:Portugal / Q000453:epidemiology; D017086:beta-Thalassemia / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*
chemical_list: D003062:Codon; D005914:Globins