Behavioral Genetics Models
chancey
Joined: 09/09/2017
Fit tests for ACE models
I am running an ACE model for an ordered categorical outcome using script adapted from [Maes](http://ibg.colorado.edu/cdrom2016/maes/UnivariateAnalysis/one/oneACEo.R). I seem to be able to generate most indicators of model fit, including AIC, BIC, -2LL and p-values associated with likelihood-ratio tests for nested models. However, I cannot seem to generate an associated chi-square value. Is there a simple way to generate chi-square value for these tests? Thanks,
Chance
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Liz
Joined: 04/20/2016
noamm
Joined: 10/10/2018
Mirch
Joined: 10/26/2018
Adding covariates to Cholesky script
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George Richardson
Joined: 10/18/2018
Sex Limitation Model Question
I attended the Boulder workshop a couple years ago and am now trying my hand at sex limitation modeling. Currently, I am working on a same-sex twin pair sex limitation model for liability to alcohol use disorder. I've found measurement invariance and A and C are invariant. C was non-sig. and is constrained to zero. The AUD factor intercept is invariant. Can I interpret the sex difference in the AUD means in terms of greater genetic risk for AUD in the males?
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Aurina
Joined: 01/05/2016
ACE including non-twin siblings
I'm trying to adapt ACE heritability model to include both twins and their non-twin siblings. The data used for the analysis are imaging-derived phenotypes from the human connectome project (HCP) which includes both MZ and DZ twin pairs as well as their non-twin siblings for a subset of twins. Would be really helpful if anyone could answer a few questions.
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sealx017
Joined: 08/17/2018
Multivariate cholesky model
I have a dataset of twins on 4 time-points. I can fit the Multivariate cholesky decompositon model with ACE components. It considers unstrcutured covariance matrices for A, C and E component. I was wondering if its possible to restrict it to a special structure? Like, say compound symmetric or AR1.
Thanks
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Cuttlefish
Joined: 09/12/2018
Different age (covariate) for siblings
I’m working on the bivariate ACE model from 2016 Boulder workshop from Hermione Maes ‘twoSATja’ and ‘twoACEja’ (http://ibg.colorado.edu/cdrom2016/maes/UnivariateAnalysis/scriptsOpenMx.shtml). I use questionnaire data and some participants filled this out one or two years later than their twin siblings, this means that some siblings differ in age. How do I adjust the model to allow different ages between twins? I keep running into problems with non-conforming arrays…
Below the parts of the script that I have trouble adapting:
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massimiliano.orri
Joined: 06/11/2018
Latent Growth Model and distal outcome
I would like to fit the twin model in the enclosed figure, but I am not sure if this is feasible.
Can someone help me understanding if the model is identified?
In case, are there any exemples of R code for this model?
Thanks a lot
M
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sealx017
Joined: 08/17/2018
Include covariates in multivariate cholesky model
Hi,
I have a dataset of twins on 4 time-points and a covariate which does not vary over time. I can fit the Multivariate cholesky decompositon model with ACE components but stuck at the case where I want to include that covariate at each time-point.
This how I was including the covariate (snp),
defSNP <- mxMatrix( type="Full", nrow=1, ncol=2, free=FALSE, labels=c("data.snp1","data.snp2"), name="snp" ) {note that snp1 corresponds to twin 1 and snp2 corresponds to twin 2)