Table 1.

Description of methods to infer self-reported ethnicity or genetic ancestry using HM450K data

Name of method	Statistical approach	Input HM450K sites	Output	Sample characteristics
				Tissue	Populationsa	Cohort location
Barfield et al. [8]	PCA	7703 DNAme sites with a 1000 genomes project SNP at the CpG site	Genetic ancestry as PC scores	Blood	Caucasian-Americans, African–Americans	USA
EPISTRUCTURE [9]	PCA	4913 DNAme sites associated with local genetic variation (mQTLs)	Genetic ancestry as PC scores	Blood	Europeans, Puerto Ricans, Mexicans	Southern Germany; USA
Zhou et al. [10]	Predictive-modeling	59/65 SNP sites	Ethnicity	Multiple	White, Black or African American, Asian	Many
PlaNET; this study	Predictive-modeling	15 SNPs; 1845 DNAme sites	Ethnicity and genetic ancestry	Placenta	Caucasians, Asians, Africans	Canada, USA

^aEthnicity/ancestry as defined in associated study