Hardy D O, Cariño C, Catterall J F, Larrea F
The Population Council, New York, New York 10021, USA.
J Clin Endocrinol Metab. 1995 Apr;80(4):1253-6. doi: 10.1210/jcem.80.4.7714097.
Steroid hormone-binding globulin in human serum displays different isoelectric focusing (IEF) patterns among individuals, suggesting genetic variation in the gene for this extracellular steroid carrier protein. Analysis of allele frequencies and family studies suggested the existence of two codominant alleles of the gene. Subsequent determination of the molecular basis of a variant of the gene was carried out using DNA from homozygous individuals from a single Belgian family. It was of interest to characterize other variant individuals to determine whether all variants identified by IEF phenotyping were caused by the same mutation or whether other mutations occurred in the gene in different populations. Previous studies identified Mexican subjects who were heterozygous for the variant IEF phenotype. Denaturing gradient gel electrophoresis was used to localize the mutation in these subjects and to purify the variant allele for DNA sequence analysis. The results show that the mutation in this population is identical to that identified in the Belgian family, and no other mutations were detected in the gene. These data represent the first analysis of steroid hormone-binding globulin gene variation in heterozygous subjects and further support the conclusion of biallelism of the gene worldwide.
人血清中的类固醇激素结合球蛋白在个体间呈现不同的等电聚焦（IEF）模式，这表明这种细胞外类固醇载体蛋白的基因存在遗传变异。等位基因频率分析和家族研究表明该基因存在两个共显性等位基因。随后，利用来自一个比利时单一家族的纯合个体的DNA，对该基因变体的分子基础进行了测定。鉴定其他变体个体以确定通过IEF表型鉴定的所有变体是否由同一突变引起，或者该基因在不同人群中是否发生其他突变，这很有意义。先前的研究鉴定出了具有变体IEF表型的杂合墨西哥受试者。变性梯度凝胶电泳用于定位这些受试者中的突变，并纯化变体等位基因以进行DNA序列分析。结果表明，该人群中的突变与在比利时家族中鉴定出的突变相同，且未在该基因中检测到其他突变。这些数据代表了对杂合受试者中类固醇激素结合球蛋白基因变异的首次分析，并进一步支持了该基因在全球范围内存在双等位基因的结论。
