title: Hb Sinai-Baltimore or alpha 2 beta (2)18(A15)Val->Gly, a silent, mildly unstable beta chain variant detected by isoelectrofocusing and high performance liquid chromatography.
abstract: Isoelectrofocusing and high performance liquid chromatographic methods were used to study an abnormal hemoglobin present in a Black male infant and his mother. The variant, named Hb Sinai-Baltimore, focused slightly behind Hb A and separated incompletely from Hb A by cation exchange high performance liquid chromatography, while the separation of the beta A and beta X chains by reversed phase high performance liquid chromatography was complete. The variant was identified through an analysis of peptides in a tryptic digest of the isolated beta X chain and by sequencing of amplified DNA which included the beta-globin gene. The Val->Gly replacement at position beta 18 (codon 18; GTG->GGG) or at the last position of the A helix decreases the stability of the variant without affecting the hematological parameters of its carrier. The propositus was a compound heterozygote for Hb Sinai-Baltimore and Hb S; the relative quantities of the two variant chains were somewhat different from those of the beta X and beta A chains in the mother with the simple Hb Sinai-Baltimore heterozygosity. An uncertainty about the alpha-globin gene status in the child prevented a further evaluation of these differences.
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta 30912-2100.
authors.forename: D D
authors.initials: DD
authors.lastname: Pobedimskaya
authors.forename: T P
authors.initials: TP
authors.lastname: Molchanova
authors.forename: R
authors.initials: R
authors.lastname: Amernick
authors.forename: M S
authors.initials: MS
authors.lastname: Druskin
authors.forename: B B
authors.initials: BB
authors.lastname: Webber
authors.forename: J B
authors.initials: JB
authors.lastname: Wilson
authors.forename: T H
authors.initials: TH
authors.lastname: Huisman
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005260:Female; D006455:Hemoglobins, Abnormal / Q000032:analysis* / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D007223:Infant; D007525:Isoelectric Focusing; D008297:Male; D009154:Mutation
chemical_list: D006455:Hemoglobins, Abnormal; C086552:hemoglobin Sinai-Baltimore