Question: Inverse Normal Transformation Of A Quantitative Trait In Gwas
0
gravatar for snp_cook12
6.0 years ago by
snp_cook120
United States
snp_cook120 wrote:

hello, I have a question, how do you inverse normally transform a quantitative trait for genetic association studies?

gwas association • 9.8k views
ADD COMMENTlink modified 22 months ago by zju.whw40 • written 6.0 years ago by snp_cook120
2
gravatar for Devon Ryan
6.0 years ago by
Devon Ryan91k
Freiburg, Germany
Devon Ryan91k wrote:

Here's a nice paper on Pubmed Central discussing issues surrounding inverse normal transforms. In general, the idea is to match the normalized rank of the trait to a quantile in a normal distribution. Have a look at equation 1 in the paper I linked to.

ADD COMMENTlink written 6.0 years ago by Devon Ryan91k
1
gravatar for zju.whw
22 months ago by
zju.whw40
China
zju.whw40 wrote:

I think the paper mentioned by Devon Ryan worths to read.

To do INT(inverse-normal transformation), you can use the R code below:

qnorm((rank(x,na.last="keep")-0.5)/sum(!is.na(x)))

See the supplement of this paper - Yang et al. Nature 2012.

ADD COMMENTlink written 22 months ago by zju.whw40
Please log in to add an answer.

Help
Access

Use of this site constitutes acceptance of our User Agreement and Privacy Policy.
Powered by Biostar version 2.3.0
Traffic: 1212 users visited in the last hour