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No user picture. liagym1 Joined: 11/06/2019

ACE with moderator- warning in output

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Behavioral Genetics Models
I'm running an ACE with moderator script, on Mx. When I drop one of the parameters (U), I receive this message-

Mx starting optimization; number of parameters = 7
*** WARNING! ***

I am not sure I have found a solution that satisfies
Kuhn-Tucker conditions for a minimum.
NAG's IFAIL parameter is 6

Looks like I got stuck here. Check the following:
1. The model is correctly specified
2. Starting values are good
3. You are not already at the solution

Posted on
No user picture. lemire Joined: 12/13/2019

Genetic correlation: two ways, two different estimates

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Behavioral Genetics Models
Hi,

I implemented two ways of calculating the genetic correlation between two phenotypes, estimated from twins (direct model of rg between A1 and A2, and Cholesky).

My two implementations are based on the path diagrams from H.H. Maes' slides 18 and 53 found at

https://vipbg.vcu.edu/media/course/HGEN619_2015/BivariateGeneticAnalysis2.pdf

I do not get the same estimates between the two methods (-0.26 vs 0.51). Below is the code with the reproducible fake data and results. The code is also attached.

Posted on
No user picture. ReddyM Joined: 10/02/2019

Ordered quantile normalization

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Behavioral Genetics Models
Can i use ordered quantile normalization, to normalize a dataset for univariate ACE model? I think not, but if i could, that would be really good.

Thanks in advance!

Posted on
No user picture. diana Joined: 04/17/2019

How to fix the genetic correlation larger than 1

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Behavioral Genetics Models
Hi everyone, I am fitting a bivariate ACE model and I am very confused about the Ra (genetic correlation of two traits) that is larger than 1. Since Ra is a correlation coefficient, it should range from -1 to 1, am I right? I don't know how to explain this result.

In the ACE model, Ra=1.37 ,Rc=-0.04, Re=0.22.
Then I fitted ADE model, Ra=0.07, Rd=NA, Re=0.22.

The results of the goodness-of-fit test between saturated model and ACE or ADE are as follows.

Posted on
No user picture. qingwen Joined: 08/15/2019

CI is confusing

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Behavioral Genetics Models
I fit a nuclear twin family model. AE model is the best. However, the CI of e makes me confused. Here are the output in free parameters and CI details section. The CI details looks strange, ranging from 0 to 2.053589e+06.

Posted on
No user picture. liagym1 Joined: 11/06/2019

ACE with moderator-help interpreting results

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Behavioral Genetics Models
I am using regular Mx (unfortunatly i cannot find an active forum), and would like to clarify the meanings of the output received after running in an ACE with an ordinal moderator script.
1. Are the estimates of T,U,V the moderated components? (often denoted by betas)
2. If the estimate for a certain parameter is not zero, yet the CI contains zero- does this imply that this component is not significant?
Posted on
No user picture. liagym1 Joined: 11/06/2019

Error in output

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Behavioral Genetics Models
I am trying to run an ACE with moderator script, and this is the error I received in the output. What changes should i make in my data?

Error found in rectangular data; record number 1 :

 1004 -999 -999 -999 -999 -999

We have a problem whose error code is 176

and which I ran across at line number 38

of your input script

RE FILE=AGE11DATA.DAT

~~~

An error has occurred while reading a rectangular file

Make sure that you *don't* have a FORMAT at the beginning

Posted on
No user picture. ReddyM Joined: 10/02/2019

Difference between optimizers

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Behavioral Genetics Models
In my twin model i calculate Rmz and Rdz from the saturated model, however when i run it (i run it on several variables) for a few variables CSOLNP fails to calculate confidence intervals, while SLSQP does caculate all. Is there a particular reason for this? Should i be concerned by this, or just use slsqp for the cases csolnp fails?

Here is the sat part, if it helps:


#sat model, rmz, rdz:

PathMZ <- mxMatrix("Lower",nrow = 2,ncol = 2,free = TRUE,values=starting_value_pathcoeff,name = "PathMZ")#cholesky for pos definitness

Posted on
No user picture. lior abramson Joined: 07/21/2017

direct comparison between traits' heritability with no raw data

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Behavioral Genetics Models
Dear forum
I am trying to conduct a meta-analysis on the heritability of two traits that are different, yet related (I found six studies in which the twins were measured in both traits).

From what I know, in order to directly compare between the two traits heritability, I need to enter them in the same model, and for that, I need either the raw data or the full correlation matrix (and I have neither).

Posted on
No user picture. George Richardson Joined: 10/18/2018

Multivariate ACE Vs. Multilevel Model

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Behavioral Genetics Models
Hi All,
I'm trying to understand the relationship between multivariate ACE models (e.g., Cholesky model fit to two phenotypes) and multilevel behavior genetic models. Is there a formal comparison somewhere?

My sense is that multivariate ACE models conflate within and between pair variance. A and C could capture within and between effects while E captures the within pair effects. E will map right onto the within pair effect in the multilevel model (MLM). Is all this correct?

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