[Gene Analysis of Combined Dual Rare Thalassemia].

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 β^{IVS II-2(-T)}/β^N heterozygous, the other was αα^{IVS-II-55(T→G) in α1}/αα^4.2-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.