摘要
目的 调查珠海市这座新兴“移民”城市中户籍人群中 β-地中海贫血 (β -地贫 )的携带率、基因突变类型及其频率分布 ,包括 β -地贫合并α -地贫的发生率。方法 连续抽取婚前对象的静脉血大样本 ,先用血液学分析法筛查 β -地贫表型阳性样品 ,再应用反向点杂交 (RDB)和gap -PCR技术分别对之进行β -地贫基因和东南亚缺失型 (- - SEA)α-地贫的定型 ,未知样品则进行DNA直接测序分析。结果 在 1,5 84例婚检对象中 ,检出 β -地贫表型阳性样品 37例 ;经基因分析 ,34例被确定了β -地贫基因型 (包括 2个小红细胞症且 3 5 %≤HbA2 <4 .0 %的病例 ) ,共检出 9种基因型并总结出它们的构成比。其余的 3例 (有 2例 3 5≤HbA2 <4 .0 %)经DNA测序未发现突变。因此 ,该市户籍人群中的 β -地贫基因携带率为2 2 %(35 / 1,5 84 ) ;9种已知β -地贫的基因频率—CD4 1- 4 2s(-CTTT)和 - 2 8(A→G)分别为 34 3%和 2 5 7%;IVS - 2nt6 5 4(C→T)和CD2 6 (G→A ,BE)、CDs71- 72 (+A)t和CD4 3(G→T)各为 8 6 %、5 7%;CD17(A→T)、- 2 9(A→G)和CDs2 7- 2 8(+C)及未知突变均为 2 85 %。值得提及的是 ,在 35例 β -地贫基因阳性样品中 ,有 2例是从 3 5 %≤HbA2 <4 .0 %样品中检出。此外 ,还从 35例
Objective: In order to investigate the prevalence, mutation spectrum and mutant allele constitution of β-thalassemia including prevalence of β-thalassemia compounded with α-thalassemia in the population of household registration in Zhuhai city. Method: The successive premarriage samples from individuals of the household registration in Zhuhai city were collected and first screened for β-thalassemia determinants with hematological method, then beta-thalassemia chromosomes and the commonest α-thalassemia gene with genotype of -- SEA/α α were determined by using reverse dot blot(RDB) and gap-PCR assays respectively in the positive samples with β-thalassemia determinants. Unknown the positive samples were assayed with DNA sequencing. Results: of all 1,584 individuals detected, 37 were to be with β-thalassemia determinants; 34 were found to carry β-thalassemia alleles including 2 cases with microcythosis and HbA 2 levels from 3.5% to 4.0%. A total of 9 β-thalassemia mutations was detected and its frequency was calculated. The β-thalassemia genotypes have not been characterized in the remaining 3 samples with β-thalassemia determinants including 2 cases with HbA 2 level from 3.5 to 4.0 percent. So,the carrier rate of β-thalassemia in Zhuhai population is 2.2%(35/1,584). Each gene frequency of the 9 β-thalassemia mutations is calculated in turn to be 34.3%(CD41-42s),25.7%(-28),8.6%(Ivs-2-nt654 and CD26),5.7%(CDs71-72(+A) and CD43) (G→T) and 2.85%(CD17,-29,CDs27-28and unknown). In addition, -- SEA was found in 4 cases with β-thalassemia mutations. Conclusion: The prevalence, mutation spectrum and mutant allele constitution of β-thalassemia in Zhuhai population are provided and β-thalassemia compounded with α-thalassemia can not neglected. it should be useful for genetic counseling and for making prevention project of thalassemia based on large-scale population screening in this area.
出处
《中国优生与遗传杂志》
2003年第5期10-11,38,共3页
Chinese Journal of Birth Health & Heredity
基金
广东省科委和广东省卫生厅联合攻关重大课题基金 (99B0 670 4G)
珠海市科委重点科技攻关基金 [(1998) 46号 -9818]资助项目
