Saturday, May 18, 2013

Prioritizing GWAS Results

This review paper mentioned 3 analytic methods to prioritizing GWAS results (for follow-up studies):
  • Meta-analysis seeks to pool information from multiple GWAS to increase the chances of finding true positives among the false positives and provides a way to combine associations across GWAS, even when the original data are unavailable.

  • Testing for epistasis within a single GWAS study can identify the stronger results that are revealed when genes interact.

  • Pathway analysis of GWAS results is used to prioritize genes and pathways within a biological context. Following a GWAS, association results can be assigned to pathways and tested in aggregate with computational tools and pathway databases.

Wednesday, May 15, 2013


The default plot function from glmnet is quite basic and plain. The following function tries to improve the plots
#this function is to achieve the same purpose of plot.glmnet()
#with the following enhancement:

# 1) show variable number instead of column number
# 2) show the value of lambda that gives smallest cross validation error with a solid line
# 3) show the largest lambda such that the error is within 1 se of the minimal cross validation error with a dashed line
 
#input variables: a glmnet object from glmnet(), a cv. glmnet object from cv.glmnet(), and a possible plot title