## Example implementing duplicate (regenotyped) data in a test ## of genetic association ## Please use the following reference when using this software: ## Reference: NL Tintle, D Gordon, F McMahon, SJ Finch ## Using duplicate genotyped data in genetic analyses: ## testing association and estimating error rates, SAGMB, 2007 ## Statistical Applications in Genetics and Molecular Biology. ## Accepted December 4, 2006. ## Script last updated 6-3-08 ## Script Author: Dirk VanBruggen, Hope College ## Contact: tintle@hope.edu ## Example: Consider a situation where 100 individuals are genotyped once ## and the other 100 individuals are genotyped twice. ## Assume we have a case-control study and so there are 100 cases ## and 100 controls. Thus, there are 50 cases that are genotyped once, ## 50 cases that are genotyped twice, 50 controls that ## are genotyped once and 50 controls that are genotyped twice. ## Assume that of the singly genotyped cases: 35 are classified AA, ## 10 are classified AB, and 5 are classified BB. While, of the ## duplicate genotpyed cases, 27 are genotyped to AA both times, ## 5 are genotyped AA once and AB once, 7 are genotyped to AB twice, ## 0 are genotyped to AA once and BB once, 2 are genotyped to AB once ## and BB once, and 9 are genotpyed to BB both times. ## Assume that of the singly classified controls: 20 are classified AA, ## 20 are classified AB, and 10 are classified BB. While, of the ## duplicate genotpyed controls, 17 are genotyped to AA both times, ## 3 are genotyped AA once and AB once, 19 are genotyped to AB twice, ## 1 is genotyped to AA once and BB once, 6 are genotyped to AB once ## and BB once, and 4 are genotpyed to BB both times. ## Then, we have a 2x3 table of singly genotyped data as follows: ## | AA | AB | BB | Total | ## ----------------------------------------------------------------- ## Cases | 35 | 10 | 5 | 50 | 100 | ## ----------------------------------------------------------------- ## Controls | 20 | 20 | 10 | 50 | 100 | ## ----------------------------------------------------------------- ## Total | 55 | 30 | 15 | 100 | 200 | ## And, we also have a 2x6 table of duplicate genotyped data as follows: ## ## | AA both | AA once | AB both | AA once | AB once | BB both | Total| ## | times |and AB once| times |and BB once |and BB once| times | | ## --------------------------------------------------------------------------------------- ## Cases | 27 | 5 | 7 | 0 | 2 | 9 | 50 | ## ------------------------------------------------------------------------------------ ##Controls | 17 | 3 | 19 | 1 | 6 | 4 | 50 | ## ------------------------------------------------------------------------------------ ## Total | 44 | 8 | 26 | 1 | 8 | 13 | 100 | ## To run the MANOVA program, create a vector of values containing the ## cell counts in the following order: ## na1,na2,na3,nu1,nu2,nu3,na11,na12,na22,na13,na23,na33,nu11,nu12,nu22, ## nu13,nu23,nu33. Thus, data=c(35,10,5,20,20,10,27,5,7,0,2,9,17,3,19,1,6,4) ## Now you can run the Manova test on the data but entering this command: ->permtest(data,0) ## Zero is used to indicate zero permutations. ## The permutation test functionality will be added in ## the near future. ## THE CODE ABOVE YIELDS THE FOLLOWING OUTPUT ## ## typicalchisq typicalpval manovats manovalpval ## [1,] 14.91082 0.0005783059 8.414398 0.000311461 ## ## Note: typicalchisq and typical pval is the value of the chisquared ## test statistic and p-value ignoring inconsistently identified ## individuals. manovats and manovapval are the values of the MANOVA ## F test statistic and p-value which includes inconsistently identified ## individuals.