“The Lost Language,” David H. Keller, MD, 1934 – The son of a wealthy family refuses to communicate in anything other than a strange series of written symbols. Only his sister is able to reach him.
Comments: Read in SF of the 30’s.
Author: Wikipedia: “David H. Keller (full name David Henry Keller; December 23, 1880–July 13, 1966) was a writer for pulp magazines in the mid-twentieth century who wrote science fiction, fantasy and horror. He was the first psychiatrist to write for the genre, and was most often published as David H. Keller, MD, but also known by the pseudonyms Monk Smith, Matthew Smith, Amy Worth, Henry Cecil, Cecilia Henry, and Jacobus Hubelaire.”… “Keller’s work often expressed strong right-wing views (Everett F. Bleiler claims he was “an ultra-conservative ideologically”), especially hostility to feminists and African-Americans.”