应用多聚酶链反应和双链DNA循环测序对FIX基因点突变的研究

STUDY ON POINT MUTATIONS OF FACTOR IX GENEWITH PCR AND DS DNA CYCLE SEQUENCING

应用多聚酶链反应扩增因子ＩＸ（ＦＩＸ）基因外显子８的４８１ｂｐＤＮＡ片段，并利用双链ＤＮＡ循环测序，对两例血友病乙ＦＩＸ基因缺陷进行了研究。发现这两例都发生在３１１１９位的碱基替换，Ｇ（ＣＧＡ）→Ａ（ＣＡＡ）。该突变为ＦＩＸ基因ＣＧ双核苷酸突变热点，改变了正常ＦＩＸ的结构和凝血功能，因而导致血友病乙。重复点突变的发现，对血友病乙分子缺陷的发病机制研究十分重要。

s DNA cycle sequencing of amplified DNA of factorIX (FIX) gene has been used to detect the molecular de-fect of hemophilia B patients. A point mutation is foundin two patients at nucleotide 31119, resulting in G(CGA) to A(CAA). This is the hot spot mutation ofFIX gene and results in a mederate reduction of FIXclotting activity. The recurrent point mutations are oftenfound to be CG dinucleotide mutations especially in exon8 of FIX gene. This is useful for gene diagnosis ofhemophilia B.