title: Mild beta-thalassemia intermedia caused by compound heterozygosity for (G)gamma((A)gammadeltabeta)(o)/beta-thalassemia and molecular characterization of the defect in four Chinese families.
abstract: Molecular characterization of the compound heterozygous condition - (G)gamma((A)gammadeltabeta)(o)/beta-thalassemia - in four families showing mild beta-thalassemia intermedia was carried out using DNA amplification techniques. Using the Amplification Refractory Mutation System (ARMS) to confirm the beta-mutations and DNA amplification to detect the 100-kb Chinese-specific (G)gamma((A)gammadeltabeta)(o)-deletion, ()two families were confirmed to possess (G)gamma((A)gammadeltabeta)(o)/beta-thalassemia with the IVSII No. 654 beta(+)-allele. In the third family, the (G)gamma((A)gammadeltabeta)(o)-deletion was confirmed in the father and the mother was a beta-thalassemia carrier with the cd 41-42 beta(o)-allele. Their affected child with (G)gamma((A)gammadeltabeta)(o)/beta-thalassemia was found to be transfusion dependent. The same (G)gamma((A)gammadeltabeta)(o)-deletion and beta-thalassemia (cd 41-42) was also confirmed in a fourth family. In addition, the mother was also diagnosed with Hb H disease (genotype -alpha(3.7)/-(SEA)). Both the children were found to possess (G)gamma((A)gammadeltabeta)(o)/beta-thalassemia but they were not transfusion dependent and this could be due to co-inheritance of alpha-thalassemia-2 (genotype-alpha(3.7)/alphaalpha) in the children together with their compound heterozygous condition.
authors.affiliation: Department of Allied Health Sciences, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia. jamatan@hotmail.com
authors.forename: Mary Anne
authors.initials: MA
authors.lastname: Tan Jin Ai
authors.forename: Sook Fan
authors.initials: SF
authors.lastname: Yap
authors.forename: Kim Lian
authors.initials: KL
authors.lastname: Tan
authors.forename: Yean Ching
authors.initials: YC
authors.lastname: Wong
authors.forename: Yong Chui
authors.initials: YC
authors.lastname: Wee
authors.forename: Juan Loong
authors.initials: JL
authors.lastname: Kok
mesh_terms: D000328:Adult; D000483:Alleles; D001797:Blood Protein Electrophoresis; D001803:Blood Transfusion; D002648:Child; D002681:China / Q000208:ethnology; D004247:DNA / Q000235:genetics; D004252:DNA Mutational Analysis; D005260:Female; D005319:Fetal Hemoglobin / Q000032:analysis; D005784:Gene Amplification; D005838:Genotype; D005914:Globins / Q000235:genetics*; D006443:Hemoglobin A2 / Q000032:analysis; D006579:Heterozygote; D006801:Humans; D008296:Malaysia; D008297:Male; D010375:Pedigree; D010641:Phenotype; D012150:Polymorphism, Restriction Fragment Length; D017384:Sequence Deletion; D017085:alpha-Thalassemia / Q000235:genetics*; D017086:beta-Thalassemia / Q000235:genetics* / Q000628:therapy
chemical_list: D005914:Globins; D004247:DNA; D006443:Hemoglobin A2; D005319:Fetal Hemoglobin