Bugvi Saima M, Imran Muhammad, Mahmood Saqib, Hafeez Rubina, Fatima Warda, Sohail Shahla
Department of Genetics, The Children's Hospital & The Institute for Child Health, Lahore, Pakistan.
Blood Coagul Fibrinolysis. 2012 Mar;23(2):132-7. doi: 10.1097/MBC.0b013e32834eb95a.
Indirect linkage analysis using highly informative polymorphic markers is the method of choice for carrier detection of hemophilia A in developing countries because direct DNA or mRNA sequence analysis is manifold costly and difficult than indirect gene tracking. Worldwide populations have revealed marked variation in the informativeness of polymorphic markers because of which each country has to select its own panel of markers for linkage analysis in hemophilia A families. The present study aimed at determining the informativeness of three factor VIII gene polymorphisms [intron 13(CA)n repeats, HindIII and AlwNI] in the Pakistani population. One hundred and forty-three individuals from 32 hemophilia A families and 68 unrelated anonymous females from the general population were screened for these polymorphisms using PCR and RFLP techniques. An inversion in intron 1 of the factor VIII gene causing 2-5% of severe hemophilia A cases was also screened in 128 Pakistani hemophilia A patients. None of the affected individuals carried the intron 1 inversion at least in peripheral blood leucocytes. The informativeness of intron 13 repeats, HindIII and AlwNI was 59.1% (13/22 hemophilia A families revealing five different alleles), 40.6% (13/32 hemophilia A families) and 6.25% (2/32 hemophilia A families), respectively. The cumulative informativeness of intron 13 repeats and HindIII was 63.6% (14/22 hemophilia A families), revealing strong linkage disequilibrium between these two polymorphic markers. These results suggest that there is a need to determine the informativeness of other polymorphic markers of the factor VIII gene to achieve 100% success rate for carrier detection of hemophilia A in Pakistan.
在发展中国家，使用信息量大的多态性标记进行间接连锁分析是检测血友病A携带者的首选方法，因为直接的DNA或mRNA序列分析比间接基因追踪成本高得多且难度大。由于全球人群中多态性标记的信息量存在显著差异，每个国家都必须选择自己的标记组合用于血友病A家系的连锁分析。本研究旨在确定巴基斯坦人群中三种凝血因子VIII基因多态性[内含子13(CA)n重复序列、HindIII和AlwNI]的信息量。使用PCR和RFLP技术对来自32个血友病A家系的143名个体和来自普通人群的68名无关匿名女性进行了这些多态性的筛查。还对128名巴基斯坦血友病A患者进行了凝血因子VIII基因内含子1倒位的筛查，该倒位导致2-5%的严重血友病A病例。至少在外周血白细胞中，没有一个受影响个体携带内含子1倒位。内含子13重复序列、HindIII和AlwNI的信息量分别为59.1%（22个血友病A家系中的13个，显示出五个不同等位基因）、40.6%（32个血友病A家系中的13个）和6.25%（32个血友病A家系中的2个）。内含子13重复序列和HindIII的累积信息量为63.6%（22个血友病A家系中的14个），表明这两个多态性标记之间存在强连锁不平衡。这些结果表明，有必要确定凝血因子VIII基因其他多态性标记的信息量，以在巴基斯坦实现100%成功检测血友病A携带者的成功率。
