Fig. 2

HTT1a expression in primary human fibroblasts can only be detected in lines with large CAG expansions

HTT1a and HTT exon 2 (HTTex2) expression in primary human fibroblast lines was analysed in lines with a CAG repeat in the control (control), adult onset (HD) or juvenile-onset range (HD juvenile). We could only detect HTT1a reliably in the lines containing very long CAG repeats (> 100). The black line represents the linear model of expression level with CAG repeat length calculated from the mean of 3 different time points in culture (see also Figure S1A). R² (coefficient of determination) and P value for the fit of the linear modelling are shown. Grey areas represent the standard error of the regression model. We did not include the line with the very large expansion in the modelling to avoid spurious fits.