Table 5.

List of Differentially-Methylated CpG Sites in Four Genes in the Replication Cohort on the Illumina 450K Platform

Gene Name (Symbol)	Total # CpG tested	CpG site differentially methylated	Absolute Mean methylation difference in PE PE–NL (% in PE)	P value	Notes
Angiotensinogen (AGT)	8	cg0750241 cg0108371	0.34-0.30 (+4%) 0.20-0.18 (+2%)	.04 .02	+ SNP; enhancer No SNP; 5’UTR
Dimethylarginine dimethylamino- hydrolase 1 (DDAH1)	45	cg24515368 cg24662614	0.87-0.85 (+2%) 0.76-0.78 (−2%)	.04 .01	No SNP; Body No SNP; N Shelf of CPI
Calcitonin-related polypeptide alpha (CALCA)	39	cg01971122 cg07529966	0.18-0.17 (+1%) 0.07-0.08 (−1%)	.03 .03	No SNP; CGI/ enhancer No SNP; CGI/Enhancer
Proopiomelanocortin (POMC)	23	cg09527270 cg03560973 cg02079741	0.75-0.79 (−4%) 0.42-0.44 (−2%) 0.57-0.60 (−3%)	.01 .05 .03	+ SNP; N Shore of CPI + SNP; N Shore of CPI No SNP; N Shore of CPI

The absolute difference in beta value was determined by subtracting the average beta value in the preeclampsia subjects at the time of delivery (PE) minus the average beta value in the normotensive subjects at the time of delivery (NL) and expressed as a percentage. A t-test was performed and a P value that was <.05 was considered significant. + SNP indicates a single nucleotide polymorphism is present in this CpG site; however, the genotype of the individual is not known. Gene locations include the gene body, CGI = CpG island; 5UTR (5 prime end untranslated region), N shores (North shore is up to 2 kilobases upstream from a CpG island) and regions that function as known enhancers. None of these CpGs differentially-methylated in the replication cohort were present on the 27k array in the discovery cohort.