Sample Size Calculation in Genetic Association Studies: A Practical Approach

Genetic association studies, testing the relationship between genetic variants and disease status, are useful tools for identifying genes that grant susceptibility to complex disorders. In such studies, an inadequate sample size may provide unreliable results: a small sample is unable to accurately describe the population, whereas a large sample makes the study expensive and complex to run. However, in genetic association studies, the sample size calculation is often overlooked or inadequately assessed for the small number of parameters included. In light of this, herein we list and discuss the role of the statistical and genetic parameters to be considered in the sample size calculation, show examples reporting incorrect estimation and, by using a genetic software program, we provide a practical approach for the assessment of the adequate sample size in a hypothetical study aimed at analyzing a gene-disease association.

Automated summary

Genetic association studies are useful for identifying genes that contribute to complex disorders. However, inadequate sample size calculation can lead to unreliable results. This article discusses the importance of considering statistical and genetic parameters in sample size calculation and provides a practical approach using genetic software to determine the appropriate sample size for a hypothetical gene-disease association study.