Navon R, Nutman J, Kopel R, Gaber L, Gadoth N, Goldman B, Nitzan M
Am J Hum Genet. 1981 Nov;33(6):907-15.
Two pairs of alleles, at the two loci of hexosaminidase (HEX), were found to segregate in an Arab inbred family: the normal and the mutant Tay-Sachs (TSD) alleles of HEX A, and the normal and a mutant allele of HEX B. Since the mutant HEX B is heat labile, no reliable identification of TSD genotypes can be obtained in its presence, as long as the proportions of HEX A and B are estimated by the routinely used heat-inactivation method. The genotypes may be correctly identified in such cases by separation of the two isoenzymes on ion-exchange chromatography, estimating their individual activities, and calculating the ratio between them. Of the nine genotype combinations possible with these two pairs of alleles, five have been identified in the reported family by this procedure.
在一个阿拉伯近交家族中发现，己糖胺酶（HEX）两个位点上的两对等位基因发生了分离：HEX A的正常等位基因和突变型泰-萨克斯病（TSD）等位基因，以及HEX B的正常等位基因和一个突变等位基因。由于突变型HEX B对热不稳定，只要通过常规使用的热灭活方法估计HEX A和B的比例，在其存在的情况下就无法获得TSD基因型的可靠鉴定结果。在这种情况下，可通过离子交换色谱法分离这两种同工酶、估计它们各自的活性并计算它们之间的比例来正确鉴定基因型。在这两对等位基因可能出现的九种基因型组合中，通过该方法已在报道的家族中鉴定出了五种。
