The introduction hits on several points that have been discussed on the forum and I think clear up many semantic issues.

There is a spectrum from strict genetic control to strict environmental control. Most diseases fall in-between. Various approaches can be used and various types of evidence can be adduced to place a disease on that spectrum. Much needs to be considered and there are sometimes known and unknown confounders. This is clearly a game for experts in this field.

I will try to figure out if there is a consensus on where AIS stands on that continuum and if so what it is.