Detecting Differentially Expressed Genes: Minimizing Burden of Testing and Maximizing Number of Discoveries

Recent progress in DNA microarray technologies allows researchers to perform genome-wide screening to detect differentially expressed genes. Under the paradigm of false discovery rate control, this paper presents sample size methods. METHODS: The author considers the following two scenarios: 1) planning the sample size to keep the 'burden of testing' ( defined as the expected number of genes that have to be tested before a true discovery can he made) below a certain level, and 2) given a fixed amount of budget, balancing the number of subjects to be recruited and the number of genes to be tested to maximize the total number of true discoveries. RESULTS: The study calculates sample sizes to minimize the burden of testing or to maximize the number of discoveries. CONCLUSIONS: The present approach to sample size calculation bears more direct relevance to gene- discovery studies