Boylan K B, Takahashi N, Diamond M, Hood L E, Prusiner S B
Am J Hum Genet. 1987 May;40(5):387-400.
A region of DNA 5' to the human myelin basic protein (MBP) gene, located on the long arm of chromosome 18, is a site of restriction-fragment-length polymorphism (RFLP) showing 37% heterozygosity in 40 subjects studied. Southern transfer analysis using a 0.9-kb genomic fragment encompassing the first exon of the human MBP gene reveals this polymorphism with at least nine restriction enzymes, indicating that insertion, deletion, or both is the basis for the DNA length variation. Double restriction-enzyme digest analysis suggests that this polymorphism is within the region 0.5-2.0 kb upstream of the coding region of the first exon of the human MBP gene. Eleven different allelic RFLPs were identified, differing in size by as many as 450 bp. The distribution of insertion/deletion-size variants from this region is bimodal, with most restriction fragments varying in size over a 0.1-kb range. Pedigree analysis of polymorphism at this site in one three-generation family shows Mendelian assortment of parental haplotypes. The form and frequency of polymorphism generated by this site is similar to that reported for human DNA regions comprised of homologous short tandem repeats.
位于18号染色体长臂上的人类髓鞘碱性蛋白（MBP）基因5'端的一段DNA区域，是一个限制性片段长度多态性（RFLP）位点，在所研究的40名受试者中显示出37%的杂合性。使用包含人类MBP基因第一个外显子的0.9 kb基因组片段进行的Southern印迹分析显示，至少有九种限制性酶可检测到这种多态性，这表明插入、缺失或两者兼而有之是DNA长度变异的基础。双重限制性酶切分析表明，这种多态性位于人类MBP基因第一个外显子编码区上游0.5 - 2.0 kb的区域内。已鉴定出11种不同的等位基因RFLP，大小差异多达450 bp。该区域插入/缺失大小变体的分布是双峰的，大多数限制性片段大小在0.1 kb范围内变化。对一个三代家族中该位点多态性的系谱分析显示，亲代单倍型符合孟德尔遗传规律。该位点产生的多态性形式和频率与报道的由同源短串联重复序列组成的人类DNA区域相似。
