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Table S1 List of models used in the simulation process. The column model refers to the number that identifies each model in the paper. X i is a fixed variable that translates an offspring genotype to a numeric value; Z i is an observed environmental covariate, either continuous or dichotomous; gim, gif are the parental genotypes (mother and father, respectively); E(X i |gim, gif) is calculated under segregation and independent assortment assumptions using Mendel's law; M = 1, 2, ..., 6 are the six possible mating types; i = 1, 2, 3, ..., n subjects; j = 1, 2, 3, ..., m measurement occasions into the subject; t ij is the repeated ozone exposure variable.

From: Gene-environment interaction tests for family studies with quantitative phenotypes: A review and extension to longitudinal measures

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)

 

χ F B A T 2 = s l o p e i - E s l o p e i * X i - E X i | g im , g if i s l o p e i - E s l o p e i 2 * Var X i | g im , g if

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)