Results from parameter-weighted linear regression.

The first column gives the weighting applied to the variant status. For each analysis, the phenotype used was log transformed CPD residuals (see Methods and mean values shown in Table 1). Carrier status was first used as an unweighted predictor of CPD, then carrier status at a subset of variant positions (those with phyloP scores >2; see Table 1). Lastly, carrier status was weighted by each of the listed parameters and used in the linear regression as the predictor. Variants of β4 were expressed with the α subunit shown, and parameter values used are in Tables 2 and 3). The columns give the slope of the relationship (β, where a negative value indicates that reduced CPD was associated with a larger value of the parameter), the adjusted r2 value and the probability that the slope is equal to zero. Associations were performed using linear regression in R.