中国汉族血友病B家系五种新的FⅨ基因突变的研究

Factor Ⅸ gene analysis in 19 unrelated patients with haemophilia B: description of 5 new mutations

目的探讨中国汉族无关血友病B家系先证者的凝血因子Ⅸ基因的突变和发病的分子机制。方法对19例中国汉族无关血友病B家系先证者,静脉采集各家系先证者外周血,表型诊断确诊后,用PCR对FⅨ8个外显子及其侧翼序列进行扩增,用末端标记双脱氧法检测核酸序列。结果19例血友病B家系先证者均检测到相应的基因序列的改变。结论19例中国汉族无亲缘关系的血友病B家系先证者FIX基因在编码外显子的核苷酸部位均发现有基因突变,其中发现五种新的突变,即6444T→A(Cys23Stop);10497G→C(Cys82Ser);31101G→T(Arg327Ile);31102InsertT;30984T→G(Ile288Ser)为国际上首次报道。

Objective Heterogeneous mutations in factor Ⅸ （FⅨ） gene cause haemophilia B and a large number of mutations have been characterized. We reported identification of 16 independent mutations including five novel mutations in 19 unrelated patients. Methods The activated partial thromboplastin time （APTI＇） ,prothrombin time （PT） and FⅨ activity（ FⅨ：C） tests were adopted for phenotype diagnosis of all the patients. All of the 8 exons and their flanks of FⅨ gene were amplified by polymerase chain reaction （PCR）. The PCR products were screened by direct sequencing. Results The 19 unrelated patients （14 severe, 4 moderate, 1 mild） had 16 different mutations in total. A single change was observed in each patient. Conclusion We use the PCR and direct sequencing technique to detect the FⅨ gene mutations in 19 unrelated patients of Han in Chinese. A single change was observed in each patient and five of the point mutations were novel nucleotide changes： T6d44A （Cys23Stop）; G10497C （Cys82Ser）; 330984G （Ile288Ser） ;G31101T（Arg327Ile） ;31102 InsertT.