Hb Suan-Dok [alpha109(G16)Leu-->Arg; CTG-->CGG (alpha2)] described in a patient of African ancestry.
A 58-year-old Black female from Curaçao (West Indies) was recently referred to our Laboratory for a persistent microcytic hypochromic anemia. An analysis 13 years earlier had shown no abnormal hemoglobin (Hb) fractions and a balanced beta/alpha synthetic ratio. The hematological indices were again compatible with thalassemia and no abnormal fractions were observed on electrophoresis or high-performance liquid chromatography (HPLC). None of the seven common alpha-thalassemia (thal) deletion defects were present. Direct sequencing of the alpha2 gene revealed a CTG-->CGG single base substitution at codon 109. This mutation was previously described in a Thai patient (Hb Suan-Dok), inducing Hb H disease in association with a - -(SEA) allele. In contrast with earlier reports we were unable to identify any native Hb fraction. The balanced beta/alpha ratio indicated that alpha2-Suan-Dok is formed but does not form tetramer formation unless alpha-thal is present.
Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands.
Marlies E
ME
Regtuijt
Cornelis L
CL
Harteveld
Peter
P
Van Delft
Nicole
N
Akkermans
Piero C
PC
Giordano
D000747:Anemia, Hypochromic / Q000235:genetics*; D044383:Black People; D005260:Female; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006801:Humans; D008875:Middle Aged; D017354:Point Mutation / Q000235:genetics*; D020836:Protein Structure, Quaternary / Q000235:genetics; D017085:alpha-Thalassemia / Q000235:genetics
D006455:Hemoglobins, Abnormal; C065341:hemoglobin Suan-Dok