Fetal Alcohol Syndrome and RAD, reasons the little boy from Russia was sent back?

If these abnormalities are so common, why is it that all the children born in Ireland, Italy, France suffering from it? In those countries, alcohol consumption is higher than the US. Why is it that FAS and RAD shows up primarily in Adoptees? Why don't children who are in their natural families show evidence of it? Could it be that, perhaps, Adoption is the cause?