title: Two different mutations in codon 68 are observed in Hb G-Philadelphia heterozygotes.
abstract: Through sequencing of amplified DNA containing the appropriate alpha-globin genes we have identified the base substitution leading to the formation of Hb G-Philadelphia [alpha 68(E17)Asn Lys]. Three subjects (approximately 25% Hb G) had an ACC AAA change at codon 68 of the alpha 2-globin gene; the chromosome with this mutation carried two alpha genes (alpha alpha). Six subjects (approximately 33% Hb G) had an AAC AAG change at the same codon of the alpha 2 alpha 1 hybrid gene on a chromosome with the 3.7 kb deletion (-alpha 3.7). These results indicate two independent mutations which likely occurred in different populations; increase in the level of Hb G is primarily dependent upon the loss of one or more alpha-globin genes.
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta.
authors.forename: T P
authors.initials: TP
authors.lastname: Molchanova
authors.forename: D D
authors.initials: DD
authors.lastname: Pobedimskaya
authors.forename: Z
authors.initials: Z
authors.lastname: Ye
authors.forename: T H
authors.initials: TH
authors.lastname: Huisman
mesh_terms: D000328:Adult; D003062:Codon; D004247:DNA / Q000032:analysis / Q000235:genetics; D005260:Female; D017353:Gene Deletion; D005914:Globins / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009154:Mutation
chemical_list: D003062:Codon; D006455:Hemoglobins, Abnormal; D005914:Globins; D004247:DNA; C031679:hemoglobin G Philadelphia