Oh, here's something interesting.

When I was spurred to read the multiple sclerosis stuff (to see if there were other diseases where an infectious+environment+genetic etiology was suggested), I noticed that they'd done some epidemiological research that showed that it was affected by latitude. Those who got more sunlight, had less MS.

Oh, I thought, wouldn't the same thing maybe be possible in scoliosis, given the whole low bone density thing? (Does everybody already know this? Well, it came as a surprise to me). Anyway, while digging around in the SOSORT articles I ran across an interesting review, and it said what I'd been unable to find. Yes, there is some thought that scoliosis is affected by latitude.

Here's the snippet:

"Epidemiology
In approximately 20% of cases, scoliosis is secondary to another pathological process. The remaining 80% are cases of idiopathic scoliosis. Adolescent idiopathic scoliosis (AIS) with a Cobb angle above 10° occurs in the general population in a wide range from 0.93 to 12% [21-38]: two to three percent is the value the most often found in the literature, and it has been suggested that epidemiology changes according to latitude [24,39]."

Article here:

http://www.scoliosisjournal.com/content/7/1/3