目的了解近年来广东地区人群中α、β珠蛋白基因的基因型分布,并对β珠蛋白基因的单核苷酸多态性(SNP)进行研究,为更准确地进行地中海贫血的遗传诊断提供理论依据。方法利用单管多重PCR检测3种5缺失型地中海贫血,采用反向杂交(RDB)/PCR技术检测α^CS、α^QS、α^WS 3种α非缺失型及中国人常见的18种β珠蛋白的基因突变,对454份广东籍受检者标本进行地中海贫血基因分型,对其中的142份标本进行变性高效液相色谱(DHPLC)分析和β珠蛋白全基因测序,分析广东地区人群β珠蛋白基因SNP。结果在438例基因分析确诊的地中海贫血患者中,α、β、αβ复合型地中海贫血分别为246、164和28例。246例5地中海贫血患者中,检出αα/--^SEA197例、αα/-α^3.7 20例、αα/-α^4.2 9例。164例β地中海贫血中,152例(92.7%)为杂合子,以CD41—42、IVS-Ⅱ-654、-28和CD17为主;8例(4.9%)为复合杂合子,4例(2.4%)为纯合子。DHPLC结合测序筛查B珠蛋白基因与RDB诊断结果一致,并发现9种SNP,其中IVS—Ⅰ-13G〉A、IVS-Ⅱ-310 T〉C未见报道。在检测标本中,有4种SNP频率较高,73.2%的患者同时合并其中3种SNP(rs713040、rs10768683、rs1609812)。结论在α地中海贫血中,主要以αα/--^SEA基因型为主;β地中海贫血以CD41—42、IVS—Ⅱ-654、-28、CD17为主要突变类型;β地中海贫血复合杂合子、纯合子及αβ复合型地中海贫血的频率较高。DHPLC结合β珠蛋白全基因测序可以快速、有效地检出常见β地中海贫血突变型。rs713040、rs10768683、rs7480526、rs1609812在筛查人群中频率较高。
Objective To understand the genotype of ct and β-globin, as well as the polymorphism of ~-globin gene in Cantonese in recent years, and to provide an effective genetic diagnosis for thalassemia (thal). Methods The single-tube complex PCR was used to detect 3 types of deletional α-thal, reverse dot blotting (RDB)/PCR to detect 3 kinds of undeletional α-thal--α^CS, α^QS, α^WS and 18 kinds of β-thal mutations which were common in Chinese population. A total of 454 cases from Guangdong were undergone thai genotype genetic diagnosis. Among the 454 cases, 142 cases were selected to perform the single nucleotide polymorphisms (SNPs) analysis of β-globin gene by denaturing high-performance liquid chromatography (DHPLC) combining the whole gent sequencing. Results Of the 454 cases, 438 were diagnosed as thalassemia, including 246 of α-thal, 164 of β-thal and 28 of αβ-thal. In 246 α-thal cases, deletions were the dominant mutations, including 197 cases of αα/--^SEA, 20 of αα/-α^3.7 and 9 of αβ-α42. In 164 β-thal cases, heterozygntes accounted for 92.7% (152/164), the main genotypes were CD41-42, IVS- Ⅱ-654,-28 and CD17, and the dual heterozygotcs and homozygotes accounted for 4.9% (8/164) and 2.4% (4/164), respectively. The result of β-globin gene screening by DHPLC combining with sequencing was consistent with that of RDB. Moreover, we also found 9 kinds of SNP, in which 2 were unreported, the IVS- Ⅰ -13 G〉 A and IVS- Ⅱ -310 T〉C. In the tested samples, the frequency of 4 kinds SNP was high, among which 3 kinds SNPs-rs713040, rs10768683 and rs1609812 were carried together. Conclusion The dominant genotypes were αα/--^SEA in α-thal cases, CD41-42, IVS- Ⅱ -654, -28 and CD17 in β-thal. The frequency of β- thal heterozygotes, homozygotes and αβ-thal is high. DHPLC combining the whole β-globin gene sequencing can effectively detect the common β-thal mutation and even new mutations or SNPs. In Cantonese, the frequency of SNP rs713040, rs10768683, rs7480526 a