Preheat oven to 350°. In a bowl or food processor, mix or whirl flour, sugar, baking powder, and salt to blend. Add butter and cut in with a pastry blender or pulse until mixture resembles coarse meal. If using a processor, scrape mixture into a bowl.
In a small bowl, whisk buttermilk and egg to blend. Add to flour mixture along with dried currants and lemon peel. Stir with a fork just until evenly moistened (dough will look crumbly).
Scrape dough onto a floured surface and, with lightly floured hands, work it into a ball, then pat into a 7-inch round about 1 3/4 inches thick. Cut dough into eight equal wedges. Arrange wedges 2 inches apart on a baking sheet.
Bake scones until tops are browned, 20 to 25 minutes. Let cool about 10 minutes on baking sheet. Meanwhile, in a small bowl, stir together powdered sugar and lemon juice. Drizzle glaze over warm scones. Serve scones warm or let cool completely.
Note: Nutritional analysis is per scone.