Harvey C B, Pratt W S, Islam I, Whitehouse D B, Swallow D M
MRC Human Biochemical Genetics Unit, Galton Laboratory, University College London, UK.
Eur J Hum Genet. 1995;3(1):27-41. doi: 10.1159/000472271.
The enzyme lactase, which is responsible for the digestion of dietary lactose, is present in the intestine of some adults but not others. As a means of providing a platform to explore the molecular basis of this nutritionally relevant genetic variation we have screened for polymorphism in several regions of the lactase gene. In each case simple polymerase chain reaction-based procedures (including single-strand conformation analysis and denaturing gradient gel electrophoresis) were used, combined with silver staining as a method of detection. Allelic variation was found at 6 different sites. One previously published polymorphism was also tested. The frequencies of the alleles were determined in more than 100 unrelated individuals of the Centre d'Etude du Polymorphisme Humain (CEPH) panel, and the haplotypes were deduced. A region of linkage disequilibrium was observed, which spans the whole coding region of the lactase gene (approximately 60-70 kb); there were only 3 common haplotypes in this population. When the CEPH sample was subdivided according to the population of origin (France or Utah) the haplotype frequencies were shown to be markedly different.
负责消化膳食乳糖的乳糖酶存在于部分成年人的肠道中，而在另一些成年人肠道中则不存在。作为探索这种与营养相关的基因变异分子基础的一个平台，我们对乳糖酶基因的几个区域进行了多态性筛选。在每种情况下，都使用了基于简单聚合酶链反应的方法（包括单链构象分析和变性梯度凝胶电泳），并结合银染作为检测方法。在6个不同位点发现了等位基因变异。还检测了一个先前发表的多态性。在人类多态性研究中心（CEPH）小组的100多个无关个体中确定了等位基因频率，并推导了单倍型。观察到一个连锁不平衡区域，它跨越乳糖酶基因的整个编码区（约60 - 70 kb）；该人群中只有3种常见单倍型。当根据来源人群（法国或犹他州）对CEPH样本进行细分时，单倍型频率显示出明显差异。
