Behavioral Genetics Models

Hi,

I am new to the twins studies field. I am hoping for help and support from this forum.

I want to analyse the gene expression data from twins in order to estimate the heritability. I have seen many studies with other phenotypes but not much with gene expression data. Has anyone worked with expression data?... can anyone point me in a correct direction?

Thanks

I am looking for advice on how to deal with huge imbalance in no of MZ and DZ pairs prior to estimating A,C and E by univariate Twin ACE model. My data set consists of 2.5 times more number of MZ pairs compare to DZ pairs.

Are there any methods available to normalize or remove the bias.

Thanks in advance.

Hi, I'm very new to openMX and I'm trying to analyse some data using ACE models. I have several data (psychological scales) about twins, and I want to calculate cross-twin and within-twin correlations between these scales. I have found such calculations are very common in papers such as this one:

http://www.ncbi.nlm.nih.gov/pubmed/21646580

and they all mention something like this:

"To estimate MZ and DZ twin correlations within and across
each of the 5 OC symptom dimensions, the data were fitted to a
constrained correlational model in Mx. The MZ and DZ correlations

Hello!
I'm trying to run a bivariate model to estimate ACE for autism and social skills. Autism has 1 threshold and social skills 5.
Do I need to specify both thresholds for the model? At the moment the script I've adapted does not do that. However, it doesn't run and returns the following error message:
"twinSat' exited abnormally with the error message: Objective function returned a value of NaN at iteration 0.1."

I want the threshold for diagnosis of autism to be above 2.3 score cut off point.

Hello

I am wondering if anyone knows of a script that would allow me to test the next step of a common pathways model. The Common Pathways model came out as the best model for my multivariate analysis, but I am now wanting to test whether another variable that I also have (but that is not currently in the model) is actually what is currently the common latent variable. Does anyone have any ideas on how I could do this?

Hello

Given that the longitudinal simplex model has measurement error at each time point built in, and that there can be transmissions from E at one time point to another,I am wondering if, at time points other than time 1 in the Simplex model, the innovation for E can be set to 0?

Many thanks

Karen

Hello again

OK today's challenge has been getting the Latent Growth curve model to work for my data. I need to covary for 4 variables (age, sex, education and marital status). I think I am having a problem with the model.
The model is reporting non-conformable arrays. I just can't find where or what I need to change. Help greatly appreciated :-)

Script is attached.

Thank you heaps in advance

Karen