Detection Probabilities for High-Risk Variants.

In each scenario there is a sporadic disease rate of 1% and the high-risk allele of interest elevates the disease risk by a factor of , which varies across columns. The rows represent increasingly restrictive sampling rules, and the probability that the high risk allele is present (one or two copies) in a sampled proband is tabulated. In the upper half of the table, risk depends only on one locus. In the lower half, there is also a nuisance locus, with a 5 percent allele frequency, i.e. 10 times as common as the allele of interest, and additive with its effect.