NMD Escape NMDetective score question

[Carly van der Heide]

Hello,

I am using the NMDetective-A and B subtracks within the new NMD Escape Track. It looks like the scoring mechanism for these subtracks is different than what is described in the Linderboom et al. 2016 paper. In the paper, the NMDetective score has a range from zero to one, but in the subtracks the score is described as "Scores range from approximately −1 to +1. Positive values indicate that a PTC at that position is predicted to trigger NMD (the mRNA is degraded). Negative values indicate that the PTC is predicted to escape NMD (the truncated mRNA may be translated into an aberrant protein). Values near zero indicate intermediate or uncertain NMD efficiency."

I am specifically looking at nonsense variants in the SCN2A gene, and I don't see any negative score values at all in any of the data I downloaded. 

Is the score range truly -1 to +1 or is this a mistake in the description?