Pharmacogenetics - Mirrored design for family-based association studies
 Responder |
 Non-responder |
The A allele is transmitted to a responder and not-transmitted to a
non-responder.
 Responder |
 Non-responder |
The A allele occurs in the responder rather than the sibling control, and in the control
rather than the non-responder.
For both TDT and sibling control methods, one can gain information from
both responders and non-responders by switching the allele counts for
one group and then adding them to the those for the first group.
Each example supports the theory that the A allele is associated with
good response.
The extension to multiallelic tests is automatic.