10个甲型血友病家系FⅧ基因突变分析

摘要

Objective To identify the F Ⅷ gene mutations of patients and suspected female carriers in 10 Hemophilia A (HA) families, and to guide the prenatal diagnosis. Methods PCR, denaturing high performance liquid chromatogramphy(DHPLC) and DNA sequencing technologies were applied to screen the FⅧ gene of 8 HA patients and 12 suspected female carriers in the 10 families. Linkage analysis was performed by using St 14 (DXS 52), intron 13 (CA)n and EX18/Bcl Ⅰ of the FⅧ gene in the HA families.In prenatal diagnosis, we screened the same mutation found in the patients. PCR-restriction fragment length polymorphism was applied to detect the new missense mutations of F Ⅷ gene in 100 unrelated healthy individuals to exclude the possibility of polymorphism. Results (1) Five missense mutations, 3 frameshift mutations, 2 nonsense mutations and 2 single nucleotide polymorphism(SNP) were identified in 10 the HA families. Among them, c. 878A＞G, c. 1015A＞G, c. 6870G＞T, c. 1282delA, c. 3072_3073insT, c. 4880_4881insA and c. 5000G＞A were novel mutations or polymorphism. No missense mutations c. 878A＞G, c.1015A＞G and c. 6870G＞T, were found in the 100 healthy unrelated controls. (2) Nine suspected female carriers were confirmed at the gene level. (3) X risk chromosome could be determined in 4 HA families by genetic linkage analysis. (4) Among the four fetuses for prenatal diagnosis, 2 were normal, 1 was carrier and the remaining 1 was a patient. Conclusion Six novel mutations, i. e. , c. 878A＞G, c. 1015A＞G, c.6870G＞T, c. 1282delA, c. 3072_3073insT and c. 4880_4881insA, were identified in this study. PCR,DHPLC and DNA sequencing could be used to screen the gene mutations of HA patients, to carry out carrier detection and prenatal diagnosis of HA families efficiently, by combining with restriction endonuclease analysis and genetic linkage analysis.%目的 分析10个家系中甲型血友病(hemophilia A,HA)患者及女性疑似携带者FⅧ基因突变,并指导产前诊断.方法 应用聚合酶链反应(polymerase chin reaction,PCR)、变性高效液相色谱技术(denaturing high performance liquid chromatogramphy,DHPLC)和DNA测序技术对10个家系中8例HA患者、12名女性疑似携带者的FⅧ基因进行突变检测,并应用St14(DXS 52)、13(CA)n、EX18/BclⅠ3个遗传标记位点对HA家系进行连锁分析.产前诊断检测已知突变位点.针对未见报道的新突变,用限制性内切酶进行分析,同时与100名表型正常的无关个体进行比较,排除多态性.结果 (1)在10个家系中发现5例错义突变、3例移码突变、2例无义突变和2个单核苷酸多态性(single nucleotide polymorphism,SNP)位点.错义突变c.878A＞G、c.1015A＞G和c.6870G＞T,移码突变c.1282delA、c3072_3073insT和c.4880_4881insA以及SNP位点c.5000 G＞A均为国际血友病网站和人类突变数据库未记载的突变或多态.在100名正常人中未检测到错义突变c.878A＞G、c.1015A＞G和c.6870G＞T.(2)在12名女性疑似携带者中,基困水平确诊9例为HA携带者,3名为正常人.(3)遗传连锁分析为4个家系提供了X风险染色体的有效信息.(4)产前诊断结果显示2例胎儿正常、1例HA携带者和1例HA患者.结论 发现c.878 A＞G、c.1015A＞G、c.6870G＞T、c.1282delA、c.3072 3073insT及c.4880_4881insA共6种能引起甲型血友病的新突变;PCR、DHPLC和DNA测序技术可有效检测甲型血友病患者基因突变,而联合限制性内切酶分析和遗传连锁分析能快速筛查HA携带者,进行有效的产前诊断.