Compute total mediation effect

The function takes in a SNP-mediator set-gene triplet and computes the total mediation effect and tests the total mediator effect via a Sobel test (1982)

sobelTest(snp, expression, mediators, covs)

Arguments

snp	vector, SNP of interest
expression	vector, gene expression of interest
mediators	data frame, mediators of interest
covs	data frame, covariates

Value

estimate of TME and Sobel test P-value