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

<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>

Analysis of hematological characteristics on the 79 co-inheritance of α-thalassemia and β-thalassemia carriers in Guangxi / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the hematological characteristics of co-inheritance of α-thalassemia (α-thal) and β-thalassemia (β-thal) and to survey the incidence of co-inheritance of α-thal and β-thal in Guangxi.</p><p><b>METHODS</b>DNA samples from 370 primary and middle school students who were β-thal carriers in Guangxi were further processed for the α-goblin gene mutation screening, and were grouped based on the genotype of β- and α-goblin gene. The hematological indexes to the different groups were compared by One-way ANOVA.</p><p><b>RESULTS</b>Of the total 370 β-thal carriers, 79 were found to carry α-thal, which gave a frequency of 21.35% for β-thal carriers and 1.36% for coincidence of these two common disorders in the local population. As expected, the 79 patients presented very variable α-globin alterations in combination with β-globin mutations, showing 31 genotype combined with the coincidence of both Hb disorders. Except the genotypes of 3 β-thal heterozygotes combined with ααα(anti3.7) triplication and 2 β-thal carriers with IVS-II-654(C→T)/N combined-α(3.7)/αα presented the phenotype of thalassemia intermedia, and other 74 carriers with co-inheritance of α-thal and β-thal all presented the phenotype of β-thal trait. There were significant differences between β-thal heterozygotes and the carriers with a co-inheritance of both β+α(0) thal in MCH, MCV and Hb. In addition, there existed significant difference between the carriers with a co-inheritance of both β+α(+) thal and a co-inheritance of both β+α(0) thal in MCV, MCH and Hb.</p><p><b>CONCLUSION</b>Compared to that of β-thal heterozygotes, the carriers with a co-inheritance of α-thal and β-thal had slighter phenotype with hematological characteristics. It's difficult to distinguish the double heterozygotes with the co-inheritance of α-thal and β-thal from β-thal heterozygotes by hematological indexes, the molecular diagnosis should be performed.</p>

Analysis of the phenotype-genotype relationship of Hb Constant Spring / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the genotype-phenotype correlations in the Hb Constant Spring (HbCS) carriers, and to investigate the effect of HbCS on hematologic parameters.</p><p><b>METHODS</b>Complete blood cell count and hemoglobin electrophoresis analyses were performed in 125 HbCS cases. The α-and β-thalassemia mutations were determined by reverse dot-blotting and Gap-PCR.</p><p><b>RESULTS</b>The presence of the SEA deletion or Hb Quong Sze (HbQS) with HbCS leads to HbH-CS disease. There was significant difference between HbH-CS and αCSα/-α, HbH-CS and αCSα/αα in the hematological parameters. The genotype of αCSα/-α or αα/αCSα had slight effect on hematological parameters. When the Hb Constant Spring mutation co-existed with heterozygous β-thalassemia, the hematological characteristics of β-thalassemia was presented. Only 57.6% of carriers with HbCS were detected by hemoglobin electrophoresis.</p><p><b>CONCLUSION</b>The cases with co-existence of HbCS trait and other α-thalassemia trait, or β-thalassemia trait, showed variation in their red blood cell parameters. For such compound heterozygotes for HbCS and other α- or β-thalassaemia mutations, which were usually misdiagnosed in clinical screening by hemoglobin electrophoresis, accurate diagnose can be made by molecular diagnosis.</p>