Kurosawa H, Yamada M, Nakagome Y
National Children's Medical Research Center, Tokyo, Japan.
Oncogene. 1987;2(1):85-90.
Using Southern blot hybridization with N-myc probes, we observed two restriction fragment length polymorphisms (RFLPs) in the Japanese population. One of the RFLPs was accounted for by the presence (allele S1) or absence (S2) of a SphI site in the second intron of the N-myc gene, and the other was explained by the presence (P1) or absence (P2) of a PvuII site in the 3' region of the gene. The allele frequencies of P1 and P2 were not significantly differently between the normal population and neuroblastoma patients with the minor allele frequency being 38-40% for P2. Frequencies of the S1 allele were 28% and 24% in neuroblastoma patients and the normal population, respectively. Fewer S1S1 homozygotes and more S1S2 heterozygotes than expected were observed in the normal population. No individuals with the S1P2 haplotype were observed due to an extreme linkage disequilibrium between the two RFLP loci. Amplification of N-myc in embryonal tumors was random with respect to the P allele, and strictly associated with the S2 allele in six cases of fresh tumors and three cases of cultured cell lines.
使用N - myc探针进行Southern印迹杂交，我们在日本人群中观察到两种限制性片段长度多态性（RFLP）。其中一种RFLP是由N - myc基因第二内含子中SphI位点的存在（等位基因S1）或缺失（S2）引起的，另一种是由该基因3'区域中PvuII位点的存在（P1）或缺失（P2）导致的。在正常人群和神经母细胞瘤患者中，P1和P2的等位基因频率没有显著差异，P2的次要等位基因频率为38 - 40%。在神经母细胞瘤患者和正常人群中，S1等位基因的频率分别为28%和24%。在正常人群中观察到的S1S1纯合子比预期的少，S1S2杂合子比预期的多。由于两个RFLP位点之间存在极端的连锁不平衡，未观察到具有S1P2单倍型的个体。在胚胎肿瘤中，N - myc的扩增相对于P等位基因是随机的，并且在6例新鲜肿瘤和3例培养细胞系中与S2等位基因严格相关。
