This one looks better and better as an N allele. We talked about it extensively previously and thought it not perfect in its habitancy distributions. But actually, it looks good. That is, it follows the idea that subSaharan Africa should be high frequency as well as Asia with Europe low to moderate and middle East quite low, Jewish being slightly higher than Arab.
The medical research on this is extensive and shows predominance of research on addiction associated with the candidate gene for N. This is consistent with the current psychiatric wisdom that addiction is a low dopamine state. And our original NPA theory by AMB which pointed out the schizophrenia link with single trait N individuals )presumably caused by damage to that single trait, be it methylation or other epigenetic events, and the research on this allele is consistent.
I wonder if AMB has any comments on the doubt that could be cast on this allele being a candidate gene for N? Also maybe AMB could find the map of this allele as I can't find it.