Ferec C, Morin J F, Parent P, Jehanne M, Chabaud J J, Gouedard G, Journel H, Saleun J P
Départemental de Transfusion Sanguine, Brest.
Arch Fr Pediatr. 1988 Oct;45(8):531-5.
We used 5 polymorphic probes strongly linked to the gene of cystic fibrosis (CF) to perform the genotypical study of 48 families with at least one child presenting with the disease. The last Km19 and XV2c probes showed a very important linkage imbalance with the CF gene (allele 2 = 6.6 kb of Km19/Pstl, chi 2 = 56; allele 1 = 2.1 kb of XV2c/Taql, chi 2 = 21). These two markers define a B haplotype which confers a relative risk of 55 to be gene carrier. From these data, the predictive value for an individual presenting with this haplotype to be heterozygous was computed to be 1/5. Presently, the risk of 1/20 for a randomized subject to be gene-carrier should be reexamined after study of this genotype. These results are very important practically, as they modify the classical data of genetic counselling concerning cystic fibrosis for the couples with a risk higher than 1/4.
我们使用了5个与囊性纤维化（CF）基因紧密连锁的多态性探针，对48个至少有一个患病孩子的家庭进行基因分型研究。最后，Km19和XV2c探针显示与CF基因存在非常重要的连锁不平衡（Km19/Pstl的等位基因2 = 6.6 kb，卡方 = 56；XV2c/TaqI的等位基因1 = 2.1 kb，卡方 = 21）。这两个标记定义了一个B单倍型，该单倍型作为基因携带者的相对风险为55。根据这些数据，计算出具有这种单倍型的个体为杂合子的预测值为1/5。目前，在研究这种基因型后，应重新审视随机个体成为基因携带者的1/20风险。这些结果在实际应用中非常重要，因为它们改变了传统的针对风险高于1/4的夫妇的囊性纤维化遗传咨询数据。
