Objective: To retrospectively analyze the detection and diagnosis process of two cases with double rare thalassemia genotypes, explore the causes of missed diagnosis and misdiagnosis of rare thalassemia, and improve the diagnosis level of rare thalassemia.
Methods: Base on the family history, hematological phenotype and hemoglobin electrophoretic analysis results, the common genotypes of α and β-thalassemia were detected by PCR+diversion hybridization. DNA sequencing technology was used for rare α and β protein genes sequencing.
Results: Both subjects were combined with double rare thalassemia genotypes, and both rare thalassemia gene combinations were reported for the first time. One of them was αβ complex thalassemia with αα*53_55 del TCC/αα heterozygous merger βIVS II-2(-T)/βN heterozygous, the other was ααIVS-II-55(T→G) in α1/αα4.2-Q double azygous heterozygous α-thalassemia, among which αα*53_55 del TCC/αα genotype was also reported for the first time.
Conclusion: The reported rare gene type αα*53_55 del TCC/αα and two cases of rare gene combinations enriches the spectrum of gene mutations in the Chinese population, and provides richer molecular information for thalassemia diagnosis and eugenics counseling.
题目: 合并双重罕见地中海贫血基因分析.
目的: 回顾性分析2例合并双重罕见型地中海贫血基因型病例的检测及诊断过程，探究罕见地中海贫血的漏诊误诊原因，提高罕见地中海贫血诊断水平。.
方法: 结合受检者家族史、血液学表型及血红蛋白电泳分析结果，采用PCR+导流杂交法检测受检者α和β-地中海贫血常见基因型，DNA测序技术对受检者标本进行罕见α和β蛋白基因测序。.
结果: 两例受检者均为合并双重罕见地中海贫血基因型，该两例罕见地中海贫血基因组合均为首次报道，一例为αα*53_55 del TCC/αα杂合合并βIVS II-2(-T)/βN杂合的αβ复合地中海贫血，另一例为ααIVS-II-55(T→G) in α1/αα4.2-Q双重杂合的α-地中海贫血，其中αα*53_55 del TCC/αα基因型亦为首次报道。.
结论: 本次报道的中国人群中罕见地中海贫血基因类型αα*53_55 del TCC/αα及两例罕见地中海贫血基因组合案例，丰富了中国人群地中海贫血基因突变谱，为地中海贫血诊断和优生优育咨询提供更丰富的分子信息。.
Keywords: αβ complex thalassemia; genetic variation; gene combination.