Genes validated by MS-Pyroseq as differentially methylated in DS versus normal PBL.

The p-values are for differential methylation from logistic regression adjusting for age. These calculations are shown both for the series including individuals with DS who provided PBL samples at multiple time points from 6 months to 7 years apart, and for same series of individuals narrowed to include only the first blood draw. As shown here, all 9 candidate loci tested by MS-Pyroseq showed highly significant differential methylation concordant with the microarray data. These results give strong confidence in the overall accuracy of the microarray data; complete lists of differentially methylated loci are in Tables S1 and S2.
aExpression summaries are from the GNF Expression Atlas 2 microarray data (http://expression.gnf.org/cgi-bin/index.cgi), Unigene (http://www.ncbi.nlm.nih.gov/UniGene/ESTProfileViewer.cgi), and microarray data in NCBI/GEO accession GDS751, see [25]. HSC, CD34+ hematopoietic stem cells.
bCGI criteria are: GC content of 50% or greater; length greater than 200 bp; ratio greater than 0.6 of observed number of CG dinucleotides to the expected number on the basis of the number of Gs and Cs in the segment.