Preheat oven to 400°F. Line a large baking sheet with parchment paper; set aside.

In a large bowl mix together flours, salt, baking powder, baking soda, sugar, and lemon zest.

Cut the butter into small cubes then quickly work it into the mixture until it resembles a coarse meal.

In a small bowl, whisk together the egg, Greek yogurt, milk, and vanilla, then add to flour and butter mixture. Stir until just moistened.

Add in the blueberries and gently fold them into dough with a spatula.

Shape the dough into an 8-inch circle, cut into 8 wedges, and transfer to the prepared sheet.

Brush each scone with the egg wash, then sprinkle with sugar.

Bake for 18-20 minutes, or until tops are lightly golden brown.

Cool for about 10 minutes, then prepare the glaze.

In a small bowl whisk together the lemon juice and confectioners sugar. Drizzle over warm scones and serve immediately.