title: alpha-thalassaemia masked by beta gene defects and a new polyadenylation site mutation on the alpha2-globin gene.
abstract: We report three examples of chronic anaemia involving complex combinations of alpha- and beta-globin gene defects. The first case had a potential Hb H disease caused by the classic SEA/RW deletions masked by Hb E [beta26(B8)Glu-->Lys] in the homozygous state. The second had an unusual Hb H disease caused by compound heterozygosity for two different alpha2 polyadenylation site mutations masked by a beta-thalassaemia heterozygosity. The third had an intermediate alpha-thalassaemia with considerable anaemia caused by an as yet unknown polyadenylation site (AATAAA>AATAAC) mutation in combination with a common RW deletion masked by a common Hb C [beta6(A3)Glu-->Lys] heterozygosity. Diagnostic methods, genotype/phenotype correlations and the chance of overlooking these combinations during risk assessment in a multiethnic society are discussed.
authors.affiliation: The Reference Hemoglobinopathies Laboratory, Department of Human and Clinical Genetics (LDGA), Leiden University Medical Center, Leiden.
authors.forename: Cornelis L
authors.initials: CL
authors.lastname: Harteveld
authors.forename: Wytze P
authors.initials: WP
authors.lastname: Oosterhuis
authors.forename: Christian H H
authors.initials: CH
authors.lastname: Schoenmakers
authors.forename: Hardjawardhama
authors.initials: H
authors.lastname: Ananta
authors.forename: Snjezana
authors.initials: S
authors.lastname: Kos
authors.forename: Margaretha
authors.initials: M
authors.lastname: Bakker Verweij
authors.forename: Peter
authors.initials: P
authors.lastname: van Delft
authors.forename: Sandra G J
authors.initials: SG
authors.lastname: Arkesteijn
authors.forename: Marion
authors.initials: M
authors.lastname: Phylipsen
authors.forename: Piero C
authors.initials: PC
authors.lastname: Giordano
mesh_terms: D000328:Adult; D005260:Female; D006455:Hemoglobins, Abnormal / Q000235:genetics; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D039104:RNA 3' Polyadenylation Signals / Q000235:genetics*; D055542:alpha-Globins / Q000235:genetics*; D017085:alpha-Thalassemia / Q000175:diagnosis / Q000235:genetics*; D055544:beta-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000235:genetics
chemical_list: D006455:Hemoglobins, Abnormal; D055542:alpha-Globins; D055544:beta-Globins