The TDT reveals linkage and linkage disequilibrium in a rare disease.

We used the TDT as the basis for our analysis of data from Problem 1 of GAW9. Among the 360 marker loci on six chromosomes, we searched for any that might show both linkage and allelic association with the disease. We applied the TDT to each allele at every marker locus and found strong evidence for linkage in two regions: one on chromosome 1, another on chromosome 5.