Synthesis of long trinucleotide repeats in vitro

More than a dozen diseases have been associated with the expansion of trinu cleotide repeats. Most of these expanding repeats are GC-rich (CGG/CCG or C TG/CAG), but it is difficult to amplify GC-rich repeat DNA from patient sam ples by the polymerase chain reaction. We invented a pair of methods to syn thesize long trinucleotide repeats in vitro by polymerase extension utilizi ng a thermal cycler. A combination of the two methods, termed the non-templ ate PCR method and SLIP (Synthesis of Long Iterative Polynucleotide) method , produced (CTG/CAG)(190) repeat DNA, We expect that these two methods will contribute to studies of all diseases associated with tri-nucleotide repea t expansion, since they can be applied to any type of repeat DNA. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.