Hi Lance,

Maybe my macro aRecodeN.sas may be applicable to you as in the example:

FILENAME AutoCall "C:\Jim\AutoCall.sas"; OPTIONS MAUTOSOURCE SASAUTOS = (AutoCall);

%aRecodeN (SourceDs=Inputds, TargetDs=OutputDs, VarList=<list of 50 SNP variables>, OldVlist=AA CC GG TT AC AG CT, NewVlist= 0 0 0 0 1 1 1 /* as desired */)

Download it from http://jim.groeneveld.eu.tf/software/SASmacro/ as aRecodeN.zip.

Regards - Jim. -- Jim Groeneveld, Netherlands Statistician, SAS consultant http://jim.groeneveld.eu.tf

My computer sorrily regrets to communicate our nogo to SGF-2010.

On Wed, 10 Mar 2010 15:53:02 -0800, Lance Smith <medicaltrial@GMAIL.COM> wrote:

>Dear all, > >I have a database of 50 SNP variables. Each SNP variable has 3 levels >let�s say AA, AG, GG. The levels vary with different SNPs, so another >one may be CC CT and TT and still another may be AA AC and CC. > >I also have levels of four markers that are on a continuous scale. >I need to do univariate linear regression to predict the level of >biomarkers using wach SNP seperately. >Thus I need to do 50*4 = 200 univariate linear regressions. >The SNPs need to be recoded to 0,1,2 for the regression as we want to >treat them as a continuous variable with the heterozygotes (AG or CT >or AC) coded as 1. > >Is there a way to efficiently do the recoding to 0,1,2 in SAS without >having to recode all the 50 SNPs separately? Or is there a way to tell >SAS to treat them as continuous variables even though they are coded >as character variables? > >Thank you