RESUMEN
<p><b>OBJECTIVE</b>To establish a novel method for the multiplex analysis of the methylation and single nucleotide polymorphism (SNP).</p><p><b>METHODS</b>The imprinted SNP rs220028 was chosen as a model. Genomic DNA, after being digested with methylation sensitive restriction enzyme, were typed by mutagenically separated PCR (MS-PCR). The polymorphism of restriction site was excluded by PCR-RFLP.</p><p><b>RESULTS</b>By post-digestion MS-PCR, the methylated allele was detected selectively, the maternal origin of which was confirmed by pedigree analysis; A=0.5085, G=0.4915,PIC=0.3749.</p><p><b>CONCLUSION</b>The multiplex analysis of methylation markers and SNP can be achieved by post-digestion MS-PCR. The imprinted SNP locus rs220028 is a potentially useful marker in screening Prader-Willi/Angelman syndrome.</p>