关键词: β地中海贫血, ^Gγ⁺(^Aγδβ)⁰地中海贫血, 基因缺失, 产前诊断

Abstract: Objective To analyse the relationship between genotype and phenotype of the deletional ^Gγ⁺(^Aγδβ)⁰-thalassemia with β thalassemia,and explore an approach to rapid prenatal diagnosis for compound heterozygotes of those defect with β-thalassemia. Methods A total of three members in a Chinese family who had a 1-year-old propositus with thalassemia major and requested prenatal diagnosis for the second pregnancy were studied.The results of phenotyping on hematological data including the RBC indices,quantification of HbF and HbA2 by Hb electrophoresis were obtained.Mutations of the β thalassemia were defined by reverse dot blot (RDB) genotyping analysis,and the deletion of ^Gγ⁺(^Aγδβ)⁰-thalassemia was analyzed using the method of gap-PCR. Results The propositus inherited the mutation of ^Gγ⁺(^Aγδβ)⁰-thalassemia gene from her mother's and inherited the frameshift mutation of CD17(A>T) from her father. Conclusion It is the first time to have performed prenatal diagnosis in Chinese family under risk of compound heterozygotes for ^Gγ⁺(^Aγδβ)⁰-thalassemia and β-thalassemia in mainland China,and this strategy to analyze the disease presented may be a valuable reference to the similar problem.

Key words: β-thalassemia, ^Gγ⁺(^Aγδβ)⁰-thalassemia, gene deletion, prenatal diagnosis