Analysis of clinical phenotypes of compound heterozygotes of Hb J-Bangkok and β-thalassemia / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To analyze hematological characteristics of compound heterozygotes of Hb J-Bangkok and β-thalassemia, and to explore the influence of Hb J-Bangkok on the phenotype of β-thalassemia.</p><p><b>METHODS</b>Peripheral blood samples from a patient carrying Hb J-Bangkok and a β-thalassemia mutation, her family members and three sporadic Hb J-Bangkok carriers were collected. RBC analysis and hemoglobin electrophoresis were performed. Genotypes of α- and β-globin genes were analyzed.</p><p><b>RESULTS</b>The father of the proband and the three sporadic cases were single carriers of Hb J-Bangkok. All of them were asymptomatic and have normal hematological parameters except for an abnormal hemoglobin band detected on hemoglobin electrophoresis. The proband was a compound heterozygote for Hb J-Bangkok and β-thalassemia mutation IVS-Ⅱ-654. She presented typical β-thalassemia trait, featuring hypochromic microcytic anemia and increased Hb A₂ level. An abnormal hemoglobin band was also detected.</p><p><b>CONCLUSION</b>Carriers of Hb J-Bangkok alone are asymptomatic. Co-existence of Hb J-Bangkok and β-thalassemia may not aggravate the phenotype. Therefore, couples with one carrying Hb J-Bangkok and another carrying a β-thalassemia mutation do not require prenatal diagnosis.</p>