Hb T-Cambodia, a beta chain variant with the mutations of Hb E and Hb D-Punjab, confirmed by DNA analysis.
Hemoglobin variants with two amino acid substitutions affecting one globin chain are relatively rare. Hb T-Cambodia, a doubly substituted beta-globin variant, was characterized previously by amino acid sequencing as having sequence alterations in beta 26 (beta 8)Glu-->Lys and beta 121(GH4) Glu-->Gln (1). It is a variant that migrates cathodic to Hb A2 on alkaline electrophoresis and with Hb A on acid citrate agar electrophoresis. We report here the mutations of Hb T-Cambodia at the nucleotide level using DNA sequencing, in beta-globin gene codon 121 (GAA-->CAA) and in codon 26 (GAG-->AAG). These are the mutations of Hb D-Punjab and Hb E, respectively.
Hutt
P J
PJ
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA.
Fairbanks
V F
VF
Thibodeau
S N
SN
Green
M M
MM
Hoyer
J D
JD
Block
S H
SH
Day
C
C
Jones
R T
RT
Barwick
R C
RC
D000328:Adult; D001797:Blood Protein Electrophoresis; D002851:Chromatography, High Pressure Liquid; D005091:Exons / Q000235:genetics; D006446:Hemoglobin E / Q000737:chemistry / Q000235:genetics; D006454:Hemoglobins / Q000032:analysis; D006455:Hemoglobins, Abnormal / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics*; D010375:Pedigree; D010455:Peptides / Q000737:chemistry; D017422:Sequence Analysis, DNA; D014357:Trypsin
D006454:Hemoglobins; D006455:Hemoglobins, Abnormal; D010455:Peptides; C106776:hemoglobin T-Cambodia; C026237:hemoglobin D Punjab; D006446:Hemoglobin E; D014357:Trypsin