Power Estimation for Gene-Longevity Association Analysis Using Concordant Twins
The concordant design and the ordinary case-control design for gene-longevity association study. The red frame represents concordant twin design in which singletons from longevity twin pairs (blue) are collected as cases. In contrast, the red frame is the ordinary case-control design in which sporadic longevity cases (blue) are sampled. Both designs use young subjects in the middle (orange) as controls.