Hello,

I am running some analyses on the HCP, testing for the heritability of mean diffusivity along along various white-matter tracts. For one of these tracts I get a H2r of 0.985 and a warning message 'Unexpectedly high heritabilities might result from numerical problems, especially if mztwins are present.' This is the case even after multiplying by the suggested factor or when I transform the data using the inverse log. I don't have this issue for the other data and when plotting them side-by-side I cannot see an obvious difference. I am not sure what numerical problems may be causing this, if it is indeed an error. Any help would be much appreciated. My model looks like this:
solarPolygenic(formula = inv_log_MeanMD_M1S1 ~ Age_in_Yrs +
Age_in_Yrs^2 + sex + Age_in_Yrs * sex + Age_in_Yrs^2 * sex +
MeanFD, data = df, covtest = TRUE, screen = TRUE)
Best wishes,
Sam
p.s Thank you for the software, I use it all the time!