Generating models | |||
---|---|---|---|
Model | Linear mixed model | Parameters | Allele frequencies |
(15) | E(Y ij |X, Z, t) = α0 + α1t ij + α2Z i + α3X i + α4X i Z i + α5X i t ij + α6Z i t ij + α7X i Z i t ij | ||
Homogeneous population | |||
α1 = -0.8; α2 = -0.2; α3 = -0.05; α4 = 0.2; α6 = 0.6; α7 = 1.0 | P(A) = 0.6 P(a) = 0.4 | ||
Admixed population | |||
α1 = -0.8; α2 = -0.2; α3 = -0.05; α4 = 0.2; α6 = 0; α7 = 1.0 | Population 1 P(A) = 0.4 P(a) = 0.6 | ||
α1 = -0.8; α2 = -0.2; α3 = -0.05; α4 = 0.2; α6 = 2.0; α7 = 1.0 | Population 2 P(A) = 0.8 P(a) = 0.2 | ||
Assessing models | |||
Model | Independent subjects design | Case-parent design | Comments |
Two-step modelling approach | |||
Main genetic effect | |||
(16) | E(slope i |X, Z) = β0 + β1X i + β2Z i | Taken from model (2) | |
(17) | E(slope i |X, Z) = β0M+ β1X i + β2Z i | Taken from model (5) | |
(18) |
| Taken from model (10) | |
Gene-environment interaction | |||
(21) | E(slope i |X, Z) = β0 + β1X i + β2Z i + β3Z i X i | Taken from model (1) | |
(22) | E(slope i |X, Z) = β0M+ β1X i + β2MZ i + β3Z i X i | Taken from model (9) | |
Models for longitudinal data | |||
Main genetic effect | |||
(19) | E(Y ij |X, Y, t) = α0 + α1t ij + α2Z i + α3X i + α4X i Z i + α5X i t ij + α6Z i t ij | Taken from model (15) with α7 = 0 | |
(20) | E(Y ij |X, Y, t) = α0M+ α1Mt ij + α2Z i + α3X i + α4X i Z i + α5X i t ij + α6MZ i t ij | Taken from model (13) with α7 = 0 | |
Gene-environment interaction | |||
(23) | E(Y ij |X, Z, t) = α0 + α1t ij + α2Z i + α3X i + α4X i Z i + α5X i t ij + α6Z i t ij + α7X i Z i t ij | Taken from model (15) | |
(24) | E(Y ij |X, Y, t) = α0M+ α1Mt ij + α2Z i + α3X i + α4X i Z i + α5X i t ij + α6MZ i t ij + α7X i Z i t ij | Taken from model (13) |