Alois Hiedler had his mother's name, Schicklgruber, because his mother was unmarried when she had him. She later married Johann Hiedler who could have been his biological father. However, it is also possible that his brother was Alois's father. DNA research on Alois's descendants has proven that they are related to the Hüttler family in Austria, who are a different branch of the Hiedler family (they liked to change the spelling of names in those days, apparently). Therefore, Alois and Adolf are true Hitlers, and this post's conclusion is false.
Austrian is pretty special. Like the language, like the people...