Family-based genetic risk prediction of multifactorial disease

Table 2 Crohn's disease simulation results

Model	AUC	R ²	T ₁	T ₅	T ₁₀
General population	0.708	0.054	7.39	4.21	3.23
P(D_I\|G_I)	0.726	0.085	15.90	5.71	3.91
P(D_I\|G_I, D_S)	0.735	0.094	15.88	5.80	3.94
P(D_I\|G_I, G_S, D_S)
Selected population (affected sibling)
P(D_I\|G_I, D_S)	0.628	0.042	71.25	60.25	53.75
P(D_I\|G_I, G_S, D_S)	0.648	0.056	82.00	67.20	58.48

Performance characteristics for tests based on the 30 Crohn's disease variants. Index individuals and their siblings were simulated in the unselected and selected (family history positive/affected sibling) scenarios. The prediction models estimate risk based on the index genotype G_I, and optionally sibling's phenotype D_Sand genotype G_S. The metrics are the area under the ROC curve (AUC), the squared correlation between disease state and risk (R²) and the relative enrichment of cases in the top 1, 5 and 10% of individuals with the highest risk scores relative to the baseline risk for that population (T₁, T₅ and T₁₀). See main text for details.

ISSN: 1756-994X