SNP-SNP interactions dominate the genetic architecture of candidate genes associated with left ventricular mass in african-americans of the GENOA study

Table 4 Outline of model improvement with addition of each SNP-SNP interaction included in final multivariable model.

Model	Interaction Terms in Model	Total # of Terms in Model	R²	Adjusted R²	LR* p-value for Additional Terms	Full Model CV* R²
1	(rs35314437 * rs7552841)	5	0.034	0.03	n/a	0.0165
2	Model 1 + (rs257376 * rs5267)	12	0.073	0.064	2.094 × 10^-8 (df = 7)	0.0332
3	Model 2 + (rs17876148 * rs12971616)	20	0.108	0.093	2.208 × 10^-7 (df = 8)	0.046
4	Model 3 + (rs6745660 * rs12460421)	28	0.133	0.113	3.631 × 10^-5 (df = 8)	0.0556

A multivariable model including a total of four SNP-SNP interactions was built in the African-American cohort of GENOA using forward selection. With the addition of each SNP-SNP interaction, along with each SNP's respective main effect, the variability in adjusted logLVM increased (assessed by adjusted R²) as did the predictive ability of the model in cross-validation test sets (assessed by full model CV R²). The final multivariable model explained 11.3% of the observed inter-individual variation in adjusted logLVM in GENOA and increased the predictive ability of the model by 5.6%.
* LR = likelihood ratio, CV = cross-validation

ISSN: 1471-2350