DXS52（St14）在血友病甲基因诊断中的方法改进及应用

Improvement and application of DXS52（St14） in gene diagnosis of hemophilia A

目的改进DXS52（St14）在血友病甲（hemophiliaA，HA）基因连锁分析中的实验方法并应用于基因诊断，报道DXS52位点与F搿基因发生重组的2个家系。方法采用PCR和琼脂糖凝胶电泳对61个非倒位HA家系的DXS52位点进行基因检测，并用FⅦ基因内的Bcl Ⅰ、HindⅢ、Xba Ⅰ、STR1、STR13、STR22和STR24这7个位点以及DXS52位点对这61个家系进行基因连锁分析。结果DXS52位点在43个HA家系中可提供信息，可诊断率为70．5％（43／61）。其中8个家系仅DXS52单个位点能提供信息，占13．1％；两个家系的DXS52与FⅦ基因发生基因重组。结论采用新的实验条件可使DXS52位点基因检测得到准确清晰的实验结果。该位点可诊断率高，目前是HA连锁基因分析中不可缺少的诊断位点，但该位点位于FⅦ基因外，与FⅦ基因间存在重组可能，单独应用于诊断时应谨慎。

Objective To improve the experimental method of DXS52 （St14） and apply it to genetic testing for hemophilia A （HA）. Methods PCR of DXS52 and agarose gel electrophoresis were performed for genetic testing in 61 non-inversion HA families. Linkage analysis of 7 loci within the FⅦ gene including Bcl Ⅰ , Hind Ⅲ, Xba Ⅰ, STR1, STR13, STR22 and STR24 were also carried out for the 61 families. Results DXS52 can provide information in 43 out of 61 families and the diagnostic rate was 70.5%. Eight families can be diagnosed only by DXS52 locus, accounting for 13. 1%. Two families were found to have recombination between DXS52 and FⅦ. Conclusion The new experimental conditions can reach accurate and clear results in DXS52 genetic testing. This gene maker has high diagnostic rate, so it is an indispensable linkage analysis method in HA gene diagnosis. More caution should be paid when using the extragenic locus DXS52 to perform gene diagnosis because of its high recombinant rate with FⅦ.