Skip to main content

Table 1 Paper, data used, and methods implemented for capturing genetic, epigenetic, and associations with phenotypes

From: The challenge of detecting genotype-by-methylation interaction: GAW20

No

Paper

Data used

GAW20 simulations

Answers known

Methods

Specific data and modeling

Response variable

1

Daw et al

Simulated

YES

GLM

Linear mixed models

Regression trees

Random forest

Simulated data (200 replications)

Simulated effect sites + noise

ave(log(TGpost))

ave.(log(TGpost)) − ave.(log(TGpre))

2

Fisher et al

Real data

N/A

Mediation interaction model

GWAS

EWAS

pairs with P1 < 10−3 and P2 < 0.05

The effect of change in methylation on change in TG differs by genotype

Power: simulation with 500 replications

logTGpost − logTGpre

3

Hu and Li

Real data

N/A

Gaussian mixture-model clustering

Gaphunter a thresholding-based method

CpG × SNP (GW) multimodal CpG sites

Association of CpG identified with overlapping SNP

Association with nearby SNPs

Pretreatment CpG

Posttreatment CpG

4

Romanescu et al

Real data

N/A

Regional-based test

Single CpG association (CH11)

Regional SNP PC association (CH11)

Regional CpG PC association (CH11)

Regional SNP + regional CpG association (CH11)

ave(ln(TGpre))

5

Sun et al

Both

YES

Adaptive W-test with 2000 repetitions to get Type I error

In both analysis main and interaction associations

Simulation: candidate pairs and noise pairs

Real data: (CH11)

delta(TG%) = 1, if delta(TG%) > 30% = 1, otherwise 0

delta(TG%) = (TGpre − TGpost)/TGpre

6

Veenstra et al

Real data

N/A

Lmekin of coxme, lm in R

(1) SNP association + (2) CpG association

(1) + (2) + CpG × SNP

Ave(TG1 + TG2) baseline

HDL

7

Zhou and Lo

Real data

N/A

Group LASSO-regression, kinship matrix, stability selection

CpG association (GW)

SNP association (GW)

(1) + (2) + CpG × SNP (CH11)

Ave(TG)

  1. Abbreviations: CH11 chromosome 11, CpG cytosine-phosphate-guanine, EWAS epigenome-wide association study, GLM generalized linear model, GW genome-wide, GWAS genome-wide association study, HDL high-density lipoprotein cholesterol, PC principal components; pre, pretreatment; post, posttreatment, SNP single-nucleotide polymorphism, TG triglyceride