Table 1 Selected results of fitting piecewise linear regression model to the data from all three allelic categories: normal, grey zone and premutation, with β₁ = 0 and thresholds at θ₁ and θ₂.

Category	Model for mean	Parameters of interest	Estimate	SE	95% CI*
Normal	α	α	0.194	0.047	(0.106 to 0.289)
Grey zone	α−β2θ1+β2xj	β2	0.037	0.013	(0.011 to 0.063)
Premutation	α−β2θ1−β3θ2+(β2+β3)xj	β2 + β3	0.008	0.002	(0.0040 to 0.012)

*Wald‐based confidence intervals.