Altered DNA Methylation in Leukocytes with Trisomy 21

The primary abnormality in Down syndrome (DS), trisomy 21, is well known, but how this chromosomal gain produces the complex DS phenotype, including immune system defects, is not well understood. We profiled DNA methylation in total peripheral blood leukocytes (PBL) and T-lymphocytes from adults with DS and normal controls and found gene-specific abnormalities of CpG methylation in DS, with many of the differentially methylated genes having known or predicted roles in lymphocyte development and function. NOTE 1: the analysis in Kerkel et al., PLOS Genet, 2010 was carried out after removing probes for genes on the X and Y chromosomes. NOTE 2: these GEO data have been analyzed with this latest version of BeadStudio; the data in the supplementary tables of Kerkel et al., PLOS Genetics, 2010, were from these same Bead chips, but extracted using an earlier version of this software. This re-extraction does not affect the conclusions in Kerkel et al., PLOS Genetics, 2010. Profiling of CpG methylation status in gene promoter regions using Illumina Infinium BeadChips.