Preheat the oven to 400. Line a baking sheet with parchment or a silicone liner and set aside.
In a medium bowl, whisk together the flour, sugar, baking powder, baking soda, and salt. Grate the cold butter into the flour mixture, and mix gently with your hands to incorporate the butter.
In a small bowl, whisk together the sour cream, egg, and vanilla. Pour the wet ingredients into the dry ingredients, and mix gently with a rubber spatula until the dough starts to come together. Gently mix in the blueberries, being careful not to crush them.
Pat the scone dough out into an 8 inch circle about 1 inch thick on a lightly floured surface. Cut the dough into 8 wedges, and place the wedges on the prepared baking sheet. Bake 15-17 minutes, until light golden brown.