Panny S R, Scott A F, Smith K D, Phillips J A, Kazazian H H, Talbot C C, Boehm C D
Am J Hum Genet. 1981 Jan;33(1):25-35.
The Hpa I restriction endonuclease site polymorphism that results in some human beta globin genes being contained in a 13-kilobase (kb) DNA restriction fragment rather than in the usual 7.6-kb fragment has been reported to be in linkage disequilibrium with the beta S mutation. The frequency of the 13-kb fragment among Baltimore black sickle cell (SS) disease patients (58%) is lower than that reported for San Francisco black SS disease patients (87%) and similar to that reported for such New York patients (59%). There is, then, considerable heterogeneity among American black populations. Therefore, for the purposes of prenatal diagnosis, the frequency in the particular population at risk should be established. When the frequency of association of the 13-kb fragment and the beta S mutation is low, the linkage phase must also be established. When the linkage phase is known, the Hpa I pattern alone can exclude SS disease 54% of the time for Baltimore AS X AS couples.
据报道，导致一些人类β珠蛋白基因包含在13千碱基（kb）的DNA限制性片段而非通常的7.6 kb片段中的Hpa I限制性内切酶位点多态性，与βS突变处于连锁不平衡状态。巴尔的摩黑人镰状细胞（SS）病患者中13 kb片段的频率（58%）低于旧金山黑人SS病患者报告的频率（87%），与纽约此类患者报告的频率（59%）相似。因此，美国黑人人群之间存在相当大的异质性。所以，为了进行产前诊断，应确定特定风险人群中的频率。当13 kb片段与βS突变的关联频率较低时，还必须确定连锁相。当连锁相已知时，仅Hpa I模式就可以在54%的时间内排除巴尔的摩AS×AS夫妇的SS病。
