Linfert D R, Rezuke W N, Tsongalis G J
Department of Pathology and Laboratory Medicine, Hartford Hospital, USA.
Conn Med. 1998 Sep;62(9):519-25.
Thromboembolic episodes are common events and affect approximately one in 1,000 persons annually. Pulmonary embolism alone accounts for 50,000 to 100,000 deaths per year in the United States with > 50% of those being elderly persons. Resistance to activated protein C is the most common inherited disorder associated with hereditary thrombophilia. A missense mutation has been identified in the gene coding for coagulation factor V (codon 506) which renders this procoagulant factor resistant to inactivation by activated protein C resulting in an increased risk for venous thrombosis. Recently, a second polymorphism was identified in the prothrombin gene (factor II) which is also associated with increased risk for venous thrombosis. Because of the high prevalence of these two mutations in the general population as well as in specific patient populations, the ability readily to detect these two mutations must be feasible. In this study, we evaluated 303 patients for the prothrombin mutatin (G20210A) which were previously tested for the factor V mutation using established polymerase chain reaction-mediated restriction fragment length polymorphism assays. In these patients, 30 (9.9%) were found to be heterozygous for the factor V Leiden mutation with no homozygous mutants identified. Twenty individuals (6.6%) were heterozygous for the prothrombin G20210A mutation, and we identified two individuals (0.66%) who were homozygous for the 20210A allele. Of the total 303 individuals screened, two were double heterozygotes for both the factor V Leiden and the prothrombin gene mutations. We also describe a multiplex polymerase chain reaction-mediated restriction fragment length polymorphism assay for detecting both mutations in a single-tube double-enzyme digestion reaction making identification of these two mutations easily achievable.
血栓栓塞事件是常见事件，每年约每1000人中就有1人受影响。仅在美国，每年肺栓塞就导致5万至10万人死亡，其中超过50%为老年人。对活化蛋白C的抵抗是与遗传性血栓形成倾向相关的最常见遗传性疾病。在凝血因子V编码基因（密码子506）中已鉴定出一种错义突变，该突变使这种促凝血因子对活化蛋白C的失活具有抗性，从而导致静脉血栓形成风险增加。最近，在凝血酶原基因（因子II）中鉴定出第二种多态性，其也与静脉血栓形成风险增加相关。由于这两种突变在普通人群以及特定患者群体中的高患病率，能够轻松检测这两种突变必须是可行的。在本研究中，我们使用既定的聚合酶链反应介导的限制性片段长度多态性分析方法，对303名患者进行了凝血酶原突变（G20210A）评估，这些患者之前已检测过因子V突变。在这些患者中，发现30人（9.9%）为因子V莱顿突变杂合子，未鉴定出纯合突变体。20人（6.6%）为凝血酶原G20210A突变杂合子，我们鉴定出2人（0.66%）为20210A等位基因纯合子。在总共筛查的303人中，有两人为因子V莱顿和凝血酶原基因突变的双重杂合子。我们还描述了一种多重聚合酶链反应介导的限制性片段长度多态性分析方法，用于在单管双酶消化反应中检测这两种突变，从而使这两种突变的鉴定易于实现。
