β-地贫合并α珠蛋白基因三联体导致中间型地贫的家系分析与产前诊断

Family analysis and prenatal diagnosis of intermediate thalassemia caused byβ-thalassemia combined withα-globin gene triplet

目的探讨分析β-地贫合并α珠蛋白基因三联体导致中间型地贫的家系分析和诊断流程,总结中间型地贫的诊断策略及产前诊断临床实践。方法通过家系成员血液学表型、常规地贫基因检测和PCR电泳法及珠蛋白基因测序技术分析β-地贫合并α珠蛋白基因三联体的临床表现;利用羊水细胞DNA对该家系1例地贫高风险胎儿进行产前诊断。结果先证者检出β-地贫CD41-42杂合突变合并αααanti4.2三联体,父亲检出αααanti4.2三联体,母亲检出β-地贫CD41-42杂合突变,胎儿结果未见异常。结论临床表现为中重度贫血的β-地贫杂合突变且未见罕见型变异,应结合临床表现与基因型是否一致,考虑可能合并α珠蛋白基因三联体导致的中间型地贫。

Objective To explore the family analysis and diagnosis process ofβ-thalassemia combined withα-globin gene triplet that results in intermediate thalassemia and to summarize the diagnostic strategy and clinical practice of intermediate thalassemia.Methods The clinical manifestations ofβ-thalassemia combined withα-globin gene triplet were analyzed by hematology phenotype of family members,routine thalassemia gene test and PCR electrophoresis and globin gene sequencing technology.The amniotic fluid cell DNA was used for prenatal diagnosis of a high-risk fetus with thalassemia in this family.Resultsβ-thalassemia CD41-42 heterozygous mutation combined with theαααanti4.2 globin triplet were detected in the proband.Theαααanti4.2 globin triplet was detected in the father,heterozygous mutation inβ-thalassemia CD41-42 was detected in the mother.The results of the fetal were not abnormal.Conclusion The heterozygous mutation ofβ-thalassemia with clinical manifestations of moderate to severe anemia and no rare type variation should be considered based on whether the clinical manifestations are consistent with the genotype,and the possible incorporation of intermediate thalassemia caused byα-globin gene triplet should be considered too.