关键词: 罕见基因型, 地中海贫血, 产前诊断

Abstract: Objective To analyze 2 families with rare thalassemia and make prenatal diagnosis thalassemia. Methods The family members' peripheral blood samples were analyzed by whole blood cell analysis and hemoglobin analysis with capillary zone electrophoresis.Conventional α and β thalassemia genes were detected by flow-through hybridization for peripheral blood samples and amniotic fluid samples.Multi-Link Probe Amplification Technology(MLPA),DNA sequencing,gap PCR (Gap-PCR) and continuous electrophoresis of hemoglobin were used to analyze the rare genotypes. Results A case of rare type of β-thalassemia with Vietnamese deletion and a case of sea deletion compound of α2 gene CD124 mutation were detected in 2 families.To prenatal diagnosis among 2 families,one of the fetuses was detected for β-thalassemia with Vietnamese deletion,another was α thalassemia with sea deletion. Conclusions When the Results of hematological phenotype and genotype do not match,much attention should be paid to further detection of rare genotypes to avoid missed diagnosis or misdiagnosis,especially to the couples who have had children with severe thalassemia.The finding may enrich knowledge of the screening in thalassemia as well as the genetic counseling and clinical diagnosis.

Key words: rare genotype, thalassemia, prenatal diagnosis