Objective:To investigate two cases of rare pathogenic genes,initiation codon mutations in HBA2 gene,combined with Southeast Asian deletion and their family members to understand the relationship of HBA2:c.2T>C and HBA2:c.2delT mutations with clinical phenotype.Methods:The peripheral blood of family members was obtained for blood cell analysis and capillary electrophoresis hemoglobin analysis.Gap-PCR and reverse dot blotting(RDB)were used to detect common types of mutations in α-thalassaemia gene.Sanger sequencing was used to analyze HBA1 and HBA2 gene sequence.Results:Two proband genotypes were identified as--SEA/αα with HBA2:c.2T>C and--SEA/αα with HBA2:c.2delT.HBA2:c.2T>C/WT and HBA2:c.2delT/WT was detected in family members.They all presented with microcytic hypochromic anemia.Conclusion:When HBA2:c.2T>C and HBA2:c.2delT are heterozygous that can lead to static α-thalassemia phenotype,and when combined with mild α-thalassemia,they can lead to the clinical manifestations of hemoglobin H disease.This study provides a basis for genetic counseling.
关键词
α-珠蛋白基因/HBA2:c.2T>C/HBA2:c.2delT/血红蛋白H病
Key words
α-globin gene/HBA2:c.2T>C/HBA2:c.2delT/hemoglobin H disease