Warner J P, Barron L H, Brock D J
Human Genetics Unit, University of Edinburgh, Western General Hospital, UK.
Mol Cell Probes. 1993 Jun;7(3):235-9. doi: 10.1006/mcpr.1993.1034.
The Huntington's Disease (HD) Collaborative Research Group has recently published the sequence of a new cDNA, IT15, containing a polymorphic trinucleotide (CAG)n repeat that is expanded and unstable on HD chromosomes. There is a correlation between the repeat size and the age of onset of symptoms. The suggested polymerase chain reaction (PCR) assay of the (CAG)n repeat requires unusual reaction components and primer concentrations and the use of 5% polyacrylamide sequencing gels to resolve the amplification products. We present a simple PCR assay that produces a smaller product using standard reaction conditions. This gives better resolution of the (CAG)n expansion observed on HD chromosomes by acrylamide gel electrophoresis and allows sufficient product to be obtained to perform assays using agarose gels. This will allow diagnostic labs to do rapid and accurate presymptomatic testing of HD in high risk families.
亨廷顿舞蹈病（HD）协作研究组最近公布了一种新的互补DNA（cDNA）——IT15的序列，它含有一个多态性三核苷酸（CAG）n重复序列，该序列在HD染色体上是扩增的且不稳定。重复序列的长度与症状出现的年龄之间存在相关性。所建议的针对（CAG）n重复序列的聚合酶链反应（PCR）检测需要特殊的反应成分、引物浓度，并且要使用5%的聚丙烯酰胺测序凝胶来分离扩增产物。我们提出了一种简单的PCR检测方法，该方法在标准反应条件下产生较小的产物。这通过丙烯酰胺凝胶电泳能更好地分辨HD染色体上观察到的（CAG）n扩增情况，并且能获得足够的产物以使用琼脂糖凝胶进行检测。这将使诊断实验室能够对高危家族中的HD进行快速且准确的症状前检测。
