Secondary erythrocytosis caused by hemoglobin Tak/(δβ)0-thalassemia syndrome.
Secondary erythrocytosis may arise from several causes, but an association with oxygen transport is rare. We describe for the first time a form of secondary erythrocytosis caused by compound heterozygosity for hemoglobin (Hb) Tak and (δβ)(0)-thalassemia found in an adult Thai individual. The patient had marked erythrocytosis and microcytosis with increased Hb and hematocrit values. Hb analyses using the Hb Gold Analyzer showed Hb A₂ (72.5%) and Hb F (30.0%) without Hb A while the capillary electrophoresis revealed 2.3% Hb A₂ and a major peak of Hb F (91.2%). Further molecular investigation identified that he was in fact a compound heterozygote for Hb Tak and deletional (δβ)(0)-thalassemia. Hematological parameters of the patient were compared with those observed for a Thai boy who demonstrated features of erythrocytosis and microcytosis caused by homozygous Hb Tak with α(+)-thalassemia and with those of pure carriers of Hb Tak and (δβ)(0)-thalassemia in our series. This report confirms the importance of both Hb and molecular investigations for the assessment of genotype/phenotype correlation and the appropriate management of the patients.
Prakobkaew
Nattaphol
N
Biomedical Science Program, Graduate School, Khon Kaen University, Khon Kaen, Thailand.
Singsanan
Sanita
S
Fucharoen
Goonnapa
G
Surapot
Satja
S
Fucharoen
Supan
S
D000328:Adult; D001483:Base Sequence; D002648:Child; D005838:Genotype; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006801:Humans; D008297:Male; D010641:Phenotype; D011086:Polycythemia / Q000209:etiology* / Q000235:genetics*; D017085:alpha-Thalassemia / Q000209:etiology / Q000235:genetics; D017086:beta-Thalassemia / Q000150:complications* / Q000235:genetics*
D006455:Hemoglobins, Abnormal; C111400:hemoglobin Tak