Compound heterozygote states for Hb C/Hb Malay and Hb C/Hb E in pregnancy: a molecular and hematological analysis.
Hemoglobin (Hb) C (alpha2beta(2)6Glu-Lys) is a variant Hb found mainly in West Africa where individuals carrying both Hb C and Hb S (alpha2beta(2)6Glu-Val) usually have a disease similar to sickle cell disease. The Hb C molecule has reduced solubility leading to crystal formation and hemolytic anemia. We report a hitherto undescribed interaction of Hb C and Hb Malay (alpha2beta(2)19Asn-Ser) in a Thai individual. She was a 24-year-old pregnant woman with moderate anemia who had the following hematologic data; Hb 8.9 g/dl, Hct 30.0%, MCV 81.0 fl, MCH 24.1 pg, MCHC 29.7 g/dl, RDW 17.1% and instead of Hb crystal a marked number of target cell in peripheral blood was observed. Hb analysis revealed 22.5% Hb Malay, 64.6% Hb C and 4.5% Hb A2. Globin gene analyses demonstrated that she carried the betaC mutation (beta6: GAG-AAG) in trans to the betaMalay mutation (beta19: AAC-AGC). Hematologic data of the patient were compared to those of the compound heterozygote for Hb C and Hb E (alpha2beta(2)26Glu-Lys) found in 5 other unrelated Thai pregnant women and 11 pregnant women with Hb C heterozygote with or without co-inheritance of alpha-thalassemia who had much lower Hb C levels and the non-pregnant women with Hb C heterozygote and a compound Hb E/Hb Malay syndrome. Different genotype-phenotype correlations observed in these Thai patients with Hb C disorders are illustrated.
Department of Clinical Chemistry, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand. supan@kku.ac.th
Supan
S
Fucharoen
Goonnapa
G
Fucharoen
Kanokwan
K
Sanchaisuriya
Satja
S
Surapot
D000328:Adult; D000743:Anemia, Hemolytic / Q000235:genetics; D004252:DNA Mutational Analysis; D005260:Female; D014644:Genetic Variation; D006444:Hemoglobin C / Q000032:analysis; D006446:Hemoglobin E; D006453:Hemoglobinopathies / Q000097:blood / Q000235:genetics*; D006455:Hemoglobins, Abnormal; D006579:Heterozygote; D006801:Humans; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000235:genetics*; D013785:Thailand
D006455:Hemoglobins, Abnormal; C063216:hemoglobin Malay; D006444:Hemoglobin C; D006446:Hemoglobin E