Psychiatric disorders in 1030 (440 DZ and 590 MZ) Caucasian female twin-pairs sampled from the Virginia Twin Registry. Lifetime psychiatric illness is a binary trait and was diagnosed using an adapted version of the Structured Clinical Interview for DSM-II-R Diagnosis.
y- Binary trait (disease presence YES - 1; NO - 0).Group- Twin zygosity (DZ - dizygotic; MZ - monozygotic).Twin- Code of twin pair.Twin_pair- Code of twin within the pair (1 and 2).
Usage
data(psydis)Source
Neale, M. C. and Maes, H. H. (2004) . Methodology for Genetic Studies of Twins and Families. Tech. rep., Virginia Common wealth University, Department of Psychiatry.
Rabe-Hesketh, S., Skrondal, A. and Gjessing, H. K. (2008) Biometrical modeling of twin and family data using standard mixed model software. Biometrics, 64, 280–288.
Bonat, W. H. and v. B. Hjelmborg, J. (2020) Multivariate Generalized Linear Models for Twin and Family data. to appear.
Examples
require(mglm4twin)
data(psydis, package="mglm4twin")
ex1_form <- y ~ 1
ex1_AE <- mt_twin(N_DZ = 440, N_MZ = 590, n_resp = 1, model = "AE")
ex1_AE <- mglm4twin(c(ex1_form), matrix_pred = ex1_AE,
link = c("logit"), variance = c("binomialP"),
data = psydis)
#> Automatic initial values selected.
summary(ex1_AE, model = "AE")
#> Call: y ~ 1
#> <environment: 0x611b732e85c0>
#>
#> Link function: logit
#> Variance function: binomialP
#> Regression:
#> Estimates std.error z value Pr(>|z|)
#> (Intercept) -0.7766975 0.05214736 -14.89428 3.590223e-50
#>
#> Dispersion:
#> Genetic component:
#> Estimates std.error z value Pr(>|z|)
#> A1 0.271778 0.03700865 7.343634 2.078717e-13
#>
#> Environment component:
#> Estimates std.error z value Pr(>|z|)
#> E1 0.7270888 0.02579587 28.18624 8.622669e-175
#>
#> Algorithm: chaser
#> Correction: FALSE
#> Number iterations: 5
summary(ex1_AE, model = "AE", biometric = TRUE)
#> Call: y ~ 1
#> <environment: 0x611b732e85c0>
#>
#> Link function: logit
#> Variance function: binomialP
#> Regression:
#> Estimates std.error z value Pr(>|z|)
#> (Intercept) -0.7766975 0.05214736 -14.89428 3.590223e-50
#>
#> Dispersion:
#> Genetic component:
#> Estimates std.error z value Pr(>|z|)
#> A1 0.271778 0.03700865 7.343634 2.078717e-13
#>
#> Environment component:
#> Estimates std.error z value Pr(>|z|)
#> E1 0.7270888 0.02579587 28.18624 8.622669e-175
#>
#> Measures associated with genetic structure:
#> Genetic correlation:
#> [1] "Univariate model no correlation available"
#>
#> Heritability:
#> Estimates std.error z value Pr(>|z|)
#> h1 0.2720863 0.03331579 8.166887 3.164496e-16
#>
#> Bivariate heritability:
#> [1] "Bivariate heritability no available."
#>
#> Measures associated with environment structure:
#> Environment correlation:
#> [1] "Univariate model no correlation available"
#>
#> Environmentality:
#> Estimates std.error z value Pr(>|z|)
#> e1 0.7279137 0.03331579 21.84891 7.961612e-106
#>
#> Bivariate environmentality:
#> [1] "Bivariate environmentality no available."
#>
#> Algorithm: chaser
#> Correction: FALSE
#> Number iterations: 5