中国广西、广东、四川三省区β-地中海贫血基因突变类型及产前基因诊断研究

Studies of β-Thalassemia Mutations and Prenatal Diagnosis in Guangxi, Guangdong and Sichuan Provinces of South China

本文采用聚合酶链反应(PCR)技术及特异寡核苷酸探针斑点杂交,分析研究广西、广东、四川三省区95例β-地中海贫血患者150 条染色体的基因突变。发现发生率最高的前两种突变各有不同。广西的是编码子41-42框架位移与17(A→T)突变。广东的是编码子41-42框架位移与IVS-Ⅱ-654突变,四川的则是17与41-42(17稍高于41-42)。-29位突变在四川也很常见,但广东、广西不多。-30位的T→C突变,IVS-Ⅰ-1的G→T以及IVS-Ⅰ-5的G→C三种突变,在本研究的病例中没有发现。并在此基础上完成了14例β-地中海贫血病危胎儿的产前基因诊断。

β-Thalassemia is one of the most common single gene disorders in South China, and ten different point mutations and frameshifts have been observed among Chinese. We studied 150 chromosomes of 95 β-thalassmia patients from Guangxi. Guangdong and Sichuan Provinces using the polymerase chain reaction followed by dot hybridzation with specific oligonucleotide probes. The most common mutations were the frameshift at codon 41-42 and the nonsense mutation at codon 17 in Guangxi and Sichuan, and the codon 41-42 frameshift and IVS-Ⅱ-654 mutation in Guangdong. The A-G mutation at -28 of the promotor was common in Sichuan but not in the other two provinces. Three mutations, -30, IVS-Ⅰ-1 and IVS-Ⅰ-5, were not observed. A prenatal diagnosis program using these tech-niques has been initiated based on these data. Fourteen pregnancies at risk for β-thalassemia have been diagnosed successfully.